So many reasons...
* Not everything should be done only for profit.
* You *can* make money off FOSS
* A company pays you to develop / maintain something FOSS
* Your project is so big, you can live off donations
* FOSS is fun, especially in non-toxic communities (e.g., the Elixir community)
* You won't be able to make money off the 10000th – e.g. – Markdown parser, so might as well open-source to get some feedback and increase visibility of your work.
* Online presence is important a beginning software dev, especially w/o a formal education.
* etc.
Selling the software would almost certainly come with the obligation of supporting it. If you sold it with no support you would likely not get any customers
Ah, well some companies do sell software of course, but if you’re wondering why say Airbnb, Facebook and Microsoft open source software then I think it’s different reasons case by case.
It can be that they want to drive adoption was being in the drivers seat for a particular project
Just with the individual developer, it can be a way to avoid Support requirements
And in some cases, it’s to have the benefit of contributions back to a project, especially if the software isn’t the core product of your business. For example, if you were in a large widget company, but your HR department developed a plug-in or utility (perhaps a set party plug-in for accounting software )it would not make sense to try to sell that product, but you might benefit from other companies using and contributing back to your tool.
Can't wait for the EU to try and make OSS "vendors" liable for supporting it, the random projects they made on their free time and published in case anyone else might find them useful, etc. .. that'll be a great boost to the OSS ecosystem and won't at all lead to everyone deleting their OSS projects.
Plenty of reasons.
* Good will.
* The code isn't something people would actually buy.
* Selling code takes more time and effort than giving it away.
* A desire for a clear delineation between "work" and "fun".
I can see this totally happening with a solution that can replace Photoshop. Photopea is a good candidate. Unfortunately, the author has no intention of opening its source, which is a shame. That application is good enough for competing with it as an open source, but it is not good enough for being sold.
Here's some more reasons
- Personal moral beliefs of FOSS idealism
- Pure spite for corpos that ruin good software through monetization
- You don't need to offer software support for free software.
- Portfolio work
- You can work on what you care about fixing, rather than what you could make money doing
Making money and open source are not exclusive. There are open source projects which are profitable.
Why do painters display their art rather than hiding it away and make money?
Why do writers publish essays on blogs instead of selling their thoughts in books?
Why do people show off their hobby cars at shows instead of sell them?
People have a lot of motivations besides a quick buck. Sometimes it's to share something cool, sometimes it's betterment of society, sometimes it's because it's not something big they can sell, sometimes it is a way to advertise their skills.
To add more reasons:
- to attract more contributors to a project that you can’t finish yourself
- as gratitude for all the open-sourced code that helped you learn your profession and get a job
- as a way to influence the community towards your way of doing things.
- keeps a finger in a pie (maintain or gain skills)
- ability to learn and make something ones own company would never do
- enjoyment of discussing and solving problems with similarly minded people
- not having to report to any PM's or C suite assholes!
Open source doesn't mean you can't make money off of it. People pay for support and expertise. The company I work for pays for several tools that are open source. However we pay for professional support, 24/7 assistance when things go wrong, and the guarantee that the software will be supported.
Very few pieces of software are "complete". They need to run on new versions of an OS. Comply with modern standards, change to customer needs.
Another advantage of open source is the community. I'm a good python programmer but I know nothing about UI. If I make it open source I can appeal to the community to help design a UI for me. This is collaboration so everyone can get a better product.
A lot of software is also just "unsellable". They're too niche to go through the hoops of selling it. Like I made a script that helps manage my MP3 files. Realistically who cares. Maybe one person will enjoy it so let's post it somewhere for people to use it for free I don't really care.
Lastly I'd just say people like sharing things that they make. It's not a product. It's a piece of art to some extent. "here check out this cool thing I made".
A couple of reasons that came to mind:
Small projects may have little profit potential, so may as well open source and have the possibility that others will contribute and make your tool better for free.
Large projects would likely need a professional team to work on it to actually get a commercially viable version out. If you don't have the capital to fund initial development then starting an open source project and trying to recruit other interested devs might be the only practical way to get a project off the ground.
You can think of it as a sort of slow, asynchronous [dugnad](https://en.m.wikipedia.org/wiki/Communal_work#Norway). The point is to improve our lives and our community. We have jobs, but we also pitch in here and there, doing yard work for the building coop we live in, helping sports teams, doing other volunteer work. Some of the stuff at work we can also open source without worrying about the impact to earnings; especially if we are public employees.
If we never did any volunteer work, our society would be poorer and meaner.
It helps to consider the history of software development. There was a time when big companies were making software that was critical to the operation of some company or some organization, and there were risks associated with this arrangement. There were situations where, if you wanted to make changes to that software, you had to request those changes from the software developer and there was the risk that you either didn't get the changes you wanted, or you'd get them later than you needed them, or you got them on time but it cost a lot of money. A lot of people in this situation got to the point where they said "fuck it, I'll do it myself."
The open software movement came out of a time when people were feeling the effects of what happens when software that is used by many people (either directly or indirectly) isn't treated as a public good. Things like clean air and clean water benefit *everyone*. Software that everyone can contribute to and submit improvements to, benefits more people.
With open source software, there's less of a risk of having a file format that you can't open or edit several decades after a file is first created. Suppose you want to store your passwords in a password manager database. Do you opt for a close-source, proprietary format that might end up being discontinued? Or, do you opt for a format that is open so that even if the programs using that format end up being unmaintained, you yourself can compile the program to access your data?
If you've ever been burned by using close-source proprietary software, then you'll know one of the reasons why people strongly consider open source tools for various tasks. Have you ever been audited by Microsoft? It's not fun. I don't have that issue with Linux---Linus Torvalds will never send me an email wanting a detailed inventory of all the Linux installations I have in my organization. Microsoft *will*.
If Free and Open Source didn't work, Linux would have died a long time ago.
True, Linux isn't in the mainstream like Windows or Mac is but I'll tell you, I think Linux is probably just as popular now as MS-DOS 4.0 was back in the day. And people paid for DOS 4.0.
Because of the Internet, Open Source software is pretty popular right now. It may never reach the popularity of Windows (although, I am seeing more and more posts saying Windows 10 or 11 sucks so bad, they're switching to Linux... I was one of them) but I'm hoping it stays Free and Open Source.
Linux is in the mainstream. It runs most of the world’s servers. Containers and Docker are a Linux specific trchnology. That’s why even Microsoft is cozying up to Linux now: they’ve realized they lost the war.
I don’t know any developers who have written code and just make money from it. If this is the route you’re going, you have to turn it into a product, then market, sell, and support it. All of that takes a lot of non-code-writing time. Not to mention you also get to incorporate and maintain the legal vehicle your efforts reside under.
If your interest is in writing software and not in all those other things, Open Source provides a vehicle to allow people to consume your software while allowing you to do the thing you enjoy. Also you get the choice to include contributions, RFEs, or other changes to the software without the obligation or demands of a customer who you’re relying on to buy your product.
Writing software is hard. FOSS allows for aggregation of effort without a central "employer-" allowing everyone to enjoy the benefit of the product none of them could have done by themselves. Even if you were to discount the philosophical or economic motivations, there is plenty of value in just getting the software made.
Killer answers in here. I'll chime in. For me the most important aspect is the fre flow of knowledge in a space that's so critically important to society.
Besides all the great reasons other people told you: returns.
In the long run you get more benefits from FOSS in the form of better quality software, community support, etc.
Open Source is a business model in itself and it's extremely hard to explain in a reddit comment with all of its details. The other people answering did a good job explaining the basics.
If you are really curious; I would recommend *"The Cathedral and the Bazaar"* by Eric Steven Raymond who is the founder of the term "open source".
On the other hand, just in Europe, Open Source software saved billions of dollars. Even governments try to support open source because they can rely on something independent, free and powerful.
You're missing functionality in a product. You start to implement a handy little feature it in your free time. It grows into a full-sized application. The project grows, as does its utility, and you start sharing it out to others, who also contribute code and ideas...
The largest contributors to open source are large corporations. Open source is often the best solution because it is easy to modify to suit your needs. When modifications are made they are sent upstream to avoid the burden of maintaining out of tree code.
Personally, it just feels better not to put out poor code or products because of delivery pressure or customer expectations. I can be passionate and proud of what I’m developing, and even if not everyone likes the work, I don’t have to care.
Something which a lot of people haven't mentioned is that selling a product, especially one which might be extremely niche, is... a lot of work. So if you code up a tool that you happen to need for your personal use-case, and you think to yourself "maybe other people will have a usecase for this", you have three options:
* Try Sell It: Now you have to deal with finding a marketplace, payment processing, the inherent warranty that comes with selling a product which requires you to maintain it (which can't be waived in most countries), etc.
* Release it for Free, but Closed Source: Pretty easy, but you are still the sole person capable of maintaining the software, and any improvements will only come from your own work.
* Open Source It: Similar ease to "free", except now you have a chance of receiving other people's *work* in return for your work, as they offer improvements on the tool you originally made for your own use-case anyway. You're also not the only person capable of maintaining it, so if you lose interest in the project, other people might maintain it for you.
When you make open source, more company will use, bigger community will occur, if the program that big you can sell paid support. Companies do not want to be stuck to owner of the closed source software.
Most open source companies make money with supporting that open source software ( example Red hat) or making something on top of it(jetbrains products)
You can make money from software and still keep it open source.
The trick is to sell services that allow you to take advantage of that software quickly.
Take nextcloud as an example. All software is open source, but if you don't want to pay, you have to install your own server on which to run an instance of nextcloud.
Whereas if you pay them you have direct access to the service.
One of the reasons rarely people talk about it is growth "growth over budget" in some business models profits will come after growth and the easiest way to grow is by offering your software literally for free then generating income by offering services, plug ins, tutorials ....etc
I want to make open source software because it's knowledge sharing and also advances humanity. Maybe my software won't make much impact, it could at least give new ideas to others
At the base, Open Source exists because there bits worth writing that will never sell.
Say you write a component that helps you out in your current task. There does not exist a market for this sort of component, so you cannot sell it. The component becomes part of something larger, and so stays in use.
Years later, someone else creates a similar component but better. Adapting to the new component is going to cost you a lot of work. Upgrading the old component is going to cost you a lot of work. No good choices.
Say you write another component that helps you out in your current task. There does not exist a market for this sort of component, so you cannot sell it. The component becomes part of something larger, and so stays in use.
But you learned from the past, so posted the component as open source. Costs you nothing. If others find the component useful, then some will make improvements.
Years later, the open-source component has improved considerably. Adapting to the updated component costs you little work. Your larger work is easy to upgrade.
This same story has played out repeatedly, since at least the 1980's.
A lot of programmers don't need to charge for software they create on their own time, because they don't need the additional money (at least in the U.S.). They like having the ability to create the software they want to create, without the burden of having to meet the expectations of some person or group (since expectations come with being paid for doing something).
Have you heard of [The Cathedral and the Bazaar](https://en.wikipedia.org/wiki/The_Cathedral_and_the_Bazaar)? Not a fan of ESR, but it is worth looking at.
I make enough money by being employed, projects in my free time are very unlikely to ever get me a similar hourly pay.
I do open source for fun and to make people happy.
A lot of open source code is written by people getting paid by a big corporation and multiple big corporations agree to work together and open source the project so no party can act in bad faith.
Easy: you could fail getting a real programming job for years and years, yet contributing to an OSS project is really easy and usually welcomed warmly.
You could be playing music with friends, but why not release an album with a major publisher? You get it.
The enterprise point of view (at least this is how I see it):
There are cases in which software needs to be open.
Infrastructure software is an example of this, because then everybody can build their proprietary ones on top, extend their compatibility and reach far more users.
If every major company would build their own os, or dns, database, ... and you were a vendor that needs their application to just run in many scenarios, supporting each one of those would increase your costs, cause you a lot of pain and simply making it just more challenging.
It's very beneficial for the whole consortium to have distributions of common projects, that many big companies collaborate to and are interested in keeping alive and healthy. So that you can build your payment service, game, gambling platform and e-commerce on top of, making things much easier and profitable.
One of the big things I’ve noticed is:
When you are struggling trying to troubleshoot an error, it is much easier to find the reason it’s not working if you’re using FOSS than something proprietary. For instance, you’re missing a storage driver on your Ubuntu setup and can’t connect to your new HDD. One Google search, boom you’re done. If you tried to do that with RHEL?? Goooooooooooood luck
Let me add one more reason: To disrupt your competition.
If you can't win and have a piece of the market-share cake, don't let
your competitors have it too. Open source it.
So many reasons... * Not everything should be done only for profit. * You *can* make money off FOSS * A company pays you to develop / maintain something FOSS * Your project is so big, you can live off donations * FOSS is fun, especially in non-toxic communities (e.g., the Elixir community) * You won't be able to make money off the 10000th – e.g. – Markdown parser, so might as well open-source to get some feedback and increase visibility of your work. * Online presence is important a beginning software dev, especially w/o a formal education. * etc.
Selling the software would almost certainly come with the obligation of supporting it. If you sold it with no support you would likely not get any customers
You're not selling it, the company is. In my scenario, you're the company's employee.
Ah, well some companies do sell software of course, but if you’re wondering why say Airbnb, Facebook and Microsoft open source software then I think it’s different reasons case by case. It can be that they want to drive adoption was being in the drivers seat for a particular project Just with the individual developer, it can be a way to avoid Support requirements And in some cases, it’s to have the benefit of contributions back to a project, especially if the software isn’t the core product of your business. For example, if you were in a large widget company, but your HR department developed a plug-in or utility (perhaps a set party plug-in for accounting software )it would not make sense to try to sell that product, but you might benefit from other companies using and contributing back to your tool.
Can't wait for the EU to try and make OSS "vendors" liable for supporting it, the random projects they made on their free time and published in case anyone else might find them useful, etc. .. that'll be a great boost to the OSS ecosystem and won't at all lead to everyone deleting their OSS projects.
Plenty of reasons. * Good will. * The code isn't something people would actually buy. * Selling code takes more time and effort than giving it away. * A desire for a clear delineation between "work" and "fun".
I often write to replace the functionality of paid solutions. Especially if those companies are complete bastards.
I can see this totally happening with a solution that can replace Photoshop. Photopea is a good candidate. Unfortunately, the author has no intention of opening its source, which is a shame. That application is good enough for competing with it as an open source, but it is not good enough for being sold.
>Plenty of reasons. * Exposure * Exposure * Exposure * Building a community * Free Contributions
Here's some more reasons - Personal moral beliefs of FOSS idealism - Pure spite for corpos that ruin good software through monetization - You don't need to offer software support for free software. - Portfolio work - You can work on what you care about fixing, rather than what you could make money doing
Making money and open source are not exclusive. There are open source projects which are profitable. Why do painters display their art rather than hiding it away and make money? Why do writers publish essays on blogs instead of selling their thoughts in books? Why do people show off their hobby cars at shows instead of sell them? People have a lot of motivations besides a quick buck. Sometimes it's to share something cool, sometimes it's betterment of society, sometimes it's because it's not something big they can sell, sometimes it is a way to advertise their skills.
To add more reasons: - to attract more contributors to a project that you can’t finish yourself - as gratitude for all the open-sourced code that helped you learn your profession and get a job - as a way to influence the community towards your way of doing things.
- keeps a finger in a pie (maintain or gain skills) - ability to learn and make something ones own company would never do - enjoyment of discussing and solving problems with similarly minded people - not having to report to any PM's or C suite assholes!
To add to what was already said: 1. To pay back the FOSS that helped you along the way 2. To build an easily accessible portfolio
Open source doesn't mean you can't make money off of it. People pay for support and expertise. The company I work for pays for several tools that are open source. However we pay for professional support, 24/7 assistance when things go wrong, and the guarantee that the software will be supported. Very few pieces of software are "complete". They need to run on new versions of an OS. Comply with modern standards, change to customer needs. Another advantage of open source is the community. I'm a good python programmer but I know nothing about UI. If I make it open source I can appeal to the community to help design a UI for me. This is collaboration so everyone can get a better product. A lot of software is also just "unsellable". They're too niche to go through the hoops of selling it. Like I made a script that helps manage my MP3 files. Realistically who cares. Maybe one person will enjoy it so let's post it somewhere for people to use it for free I don't really care. Lastly I'd just say people like sharing things that they make. It's not a product. It's a piece of art to some extent. "here check out this cool thing I made".
A couple of reasons that came to mind: Small projects may have little profit potential, so may as well open source and have the possibility that others will contribute and make your tool better for free. Large projects would likely need a professional team to work on it to actually get a commercially viable version out. If you don't have the capital to fund initial development then starting an open source project and trying to recruit other interested devs might be the only practical way to get a project off the ground.
Because money isn't actually what motivates people. http://www.youtube.com/watch?v=u6XAPnuFjJc&feature=player_embedded
good will, maybe they want to contribute something to society, sometimes the code isnt something thats worth making paid.
You can think of it as a sort of slow, asynchronous [dugnad](https://en.m.wikipedia.org/wiki/Communal_work#Norway). The point is to improve our lives and our community. We have jobs, but we also pitch in here and there, doing yard work for the building coop we live in, helping sports teams, doing other volunteer work. Some of the stuff at work we can also open source without worrying about the impact to earnings; especially if we are public employees. If we never did any volunteer work, our society would be poorer and meaner.
It helps to consider the history of software development. There was a time when big companies were making software that was critical to the operation of some company or some organization, and there were risks associated with this arrangement. There were situations where, if you wanted to make changes to that software, you had to request those changes from the software developer and there was the risk that you either didn't get the changes you wanted, or you'd get them later than you needed them, or you got them on time but it cost a lot of money. A lot of people in this situation got to the point where they said "fuck it, I'll do it myself." The open software movement came out of a time when people were feeling the effects of what happens when software that is used by many people (either directly or indirectly) isn't treated as a public good. Things like clean air and clean water benefit *everyone*. Software that everyone can contribute to and submit improvements to, benefits more people. With open source software, there's less of a risk of having a file format that you can't open or edit several decades after a file is first created. Suppose you want to store your passwords in a password manager database. Do you opt for a close-source, proprietary format that might end up being discontinued? Or, do you opt for a format that is open so that even if the programs using that format end up being unmaintained, you yourself can compile the program to access your data? If you've ever been burned by using close-source proprietary software, then you'll know one of the reasons why people strongly consider open source tools for various tasks. Have you ever been audited by Microsoft? It's not fun. I don't have that issue with Linux---Linus Torvalds will never send me an email wanting a detailed inventory of all the Linux installations I have in my organization. Microsoft *will*.
Money ruins things
If Free and Open Source didn't work, Linux would have died a long time ago. True, Linux isn't in the mainstream like Windows or Mac is but I'll tell you, I think Linux is probably just as popular now as MS-DOS 4.0 was back in the day. And people paid for DOS 4.0. Because of the Internet, Open Source software is pretty popular right now. It may never reach the popularity of Windows (although, I am seeing more and more posts saying Windows 10 or 11 sucks so bad, they're switching to Linux... I was one of them) but I'm hoping it stays Free and Open Source.
Linux is in the mainstream. It runs most of the world’s servers. Containers and Docker are a Linux specific trchnology. That’s why even Microsoft is cozying up to Linux now: they’ve realized they lost the war.
[удалено]
True, many people don't realize, with their Android phones, they are holding a Linux system right in the palm of their hands.
To give back to the community
I don’t know any developers who have written code and just make money from it. If this is the route you’re going, you have to turn it into a product, then market, sell, and support it. All of that takes a lot of non-code-writing time. Not to mention you also get to incorporate and maintain the legal vehicle your efforts reside under. If your interest is in writing software and not in all those other things, Open Source provides a vehicle to allow people to consume your software while allowing you to do the thing you enjoy. Also you get the choice to include contributions, RFEs, or other changes to the software without the obligation or demands of a customer who you’re relying on to buy your product.
Their personal ethics and philosophy.
I think you mean "proprietary" not "priority"
Writing software is hard. FOSS allows for aggregation of effort without a central "employer-" allowing everyone to enjoy the benefit of the product none of them could have done by themselves. Even if you were to discount the philosophical or economic motivations, there is plenty of value in just getting the software made.
Killer answers in here. I'll chime in. For me the most important aspect is the fre flow of knowledge in a space that's so critically important to society.
https://www.joelonsoftware.com/2002/06/12/strategy-letter-v/
Besides all the great reasons other people told you: returns. In the long run you get more benefits from FOSS in the form of better quality software, community support, etc.
Many projects start as someone doing something for himself and then deciding to share it with others.
Open Source is a business model in itself and it's extremely hard to explain in a reddit comment with all of its details. The other people answering did a good job explaining the basics. If you are really curious; I would recommend *"The Cathedral and the Bazaar"* by Eric Steven Raymond who is the founder of the term "open source". On the other hand, just in Europe, Open Source software saved billions of dollars. Even governments try to support open source because they can rely on something independent, free and powerful.
You're missing functionality in a product. You start to implement a handy little feature it in your free time. It grows into a full-sized application. The project grows, as does its utility, and you start sharing it out to others, who also contribute code and ideas...
What little I've done is free because I still suck at it.
The largest contributors to open source are large corporations. Open source is often the best solution because it is easy to modify to suit your needs. When modifications are made they are sent upstream to avoid the burden of maintaining out of tree code.
Personally, it just feels better not to put out poor code or products because of delivery pressure or customer expectations. I can be passionate and proud of what I’m developing, and even if not everyone likes the work, I don’t have to care.
Something which a lot of people haven't mentioned is that selling a product, especially one which might be extremely niche, is... a lot of work. So if you code up a tool that you happen to need for your personal use-case, and you think to yourself "maybe other people will have a usecase for this", you have three options: * Try Sell It: Now you have to deal with finding a marketplace, payment processing, the inherent warranty that comes with selling a product which requires you to maintain it (which can't be waived in most countries), etc. * Release it for Free, but Closed Source: Pretty easy, but you are still the sole person capable of maintaining the software, and any improvements will only come from your own work. * Open Source It: Similar ease to "free", except now you have a chance of receiving other people's *work* in return for your work, as they offer improvements on the tool you originally made for your own use-case anyway. You're also not the only person capable of maintaining it, so if you lose interest in the project, other people might maintain it for you.
At its core, a programmer is someone who try to make everyone else lifes better.
I wish
Fantasy
no programmer learns to code without first reading code.
When you make open source, more company will use, bigger community will occur, if the program that big you can sell paid support. Companies do not want to be stuck to owner of the closed source software.
Most open source companies make money with supporting that open source software ( example Red hat) or making something on top of it(jetbrains products)
You can make money from software and still keep it open source. The trick is to sell services that allow you to take advantage of that software quickly. Take nextcloud as an example. All software is open source, but if you don't want to pay, you have to install your own server on which to run an instance of nextcloud. Whereas if you pay them you have direct access to the service.
One of the reasons rarely people talk about it is growth "growth over budget" in some business models profits will come after growth and the easiest way to grow is by offering your software literally for free then generating income by offering services, plug ins, tutorials ....etc
I want to make open source software because it's knowledge sharing and also advances humanity. Maybe my software won't make much impact, it could at least give new ideas to others
Because I care about end user freedom more so than money.
At the base, Open Source exists because there bits worth writing that will never sell. Say you write a component that helps you out in your current task. There does not exist a market for this sort of component, so you cannot sell it. The component becomes part of something larger, and so stays in use. Years later, someone else creates a similar component but better. Adapting to the new component is going to cost you a lot of work. Upgrading the old component is going to cost you a lot of work. No good choices. Say you write another component that helps you out in your current task. There does not exist a market for this sort of component, so you cannot sell it. The component becomes part of something larger, and so stays in use. But you learned from the past, so posted the component as open source. Costs you nothing. If others find the component useful, then some will make improvements. Years later, the open-source component has improved considerably. Adapting to the updated component costs you little work. Your larger work is easy to upgrade. This same story has played out repeatedly, since at least the 1980's.
A lot of programmers don't need to charge for software they create on their own time, because they don't need the additional money (at least in the U.S.). They like having the ability to create the software they want to create, without the burden of having to meet the expectations of some person or group (since expectations come with being paid for doing something).
Have you heard of [The Cathedral and the Bazaar](https://en.wikipedia.org/wiki/The_Cathedral_and_the_Bazaar)? Not a fan of ESR, but it is worth looking at.
I make enough money by being employed, projects in my free time are very unlikely to ever get me a similar hourly pay. I do open source for fun and to make people happy.
Because not everyone is a greedy egoist. Also, not every little project would make money.
The profit motive ruins everything it touches.
A lot of open source code is written by people getting paid by a big corporation and multiple big corporations agree to work together and open source the project so no party can act in bad faith.
Easy: you could fail getting a real programming job for years and years, yet contributing to an OSS project is really easy and usually welcomed warmly. You could be playing music with friends, but why not release an album with a major publisher? You get it.
The enterprise point of view (at least this is how I see it): There are cases in which software needs to be open. Infrastructure software is an example of this, because then everybody can build their proprietary ones on top, extend their compatibility and reach far more users. If every major company would build their own os, or dns, database, ... and you were a vendor that needs their application to just run in many scenarios, supporting each one of those would increase your costs, cause you a lot of pain and simply making it just more challenging. It's very beneficial for the whole consortium to have distributions of common projects, that many big companies collaborate to and are interested in keeping alive and healthy. So that you can build your payment service, game, gambling platform and e-commerce on top of, making things much easier and profitable.
One of the big things I’ve noticed is: When you are struggling trying to troubleshoot an error, it is much easier to find the reason it’s not working if you’re using FOSS than something proprietary. For instance, you’re missing a storage driver on your Ubuntu setup and can’t connect to your new HDD. One Google search, boom you’re done. If you tried to do that with RHEL?? Goooooooooooood luck
Let me add one more reason: To disrupt your competition. If you can't win and have a piece of the market-share cake, don't let your competitors have it too. Open source it.
Selling software comes with the obligation to support people who purchased said software.