I think you're making a weak argument for how easy it is to "open source" something. Sure, publicly releasing the source code might be easy, but that's not what 'open sourcing' means to most people.
You're right tho that they could do everything you describe, i.e. publish the source code and not actually participate in any 'open source' community projects that might spring up around the code. I'm guessing that's not really that attractive to Stripe, or lots of other people. It's work just to remember to push commits to the public repo, even if you're otherwise ignoring all public communications about the project. (And ignoring all the public communications, e.g. blog posts complaining about the company not collaborating with the community, is work too.)
> Sure, publicly releasing the source code might be easy, but that's not what 'open sourcing' means to most people.
Still, if they are upfront about it, I don't see how it's an issue. If one of the first lines of the readme is something along the lines of "Because we believe in open source, we are making the source code publicly available for this product. We hope you may learn from it as much as we have, and perhaps adapt and use it in your own organization. However, there are currently no resources allocated towards making this a plug 'n play product for others (we are not your software development team) and therefore we will not accept pull requests or issues."
Perhaps that sounds a bit harsh in its current form, but this is just a draft of what it could say. I think the vast majority of people would understand that it is indeed unreasonable to expect them to spend money on your whims and wishes for no good reason.
I don't think most maintainers of open source projects would agree with your optimistic expectations about the reasonableness of the vast majority of people.
You're right tho that they could do everything you describe, i.e. publish the source code and not actually participate in any 'open source' community projects that might spring up around the code. I'm guessing that's not really that attractive to Stripe, or lots of other people. It's work just to remember to push commits to the public repo, even if you're otherwise ignoring all public communications about the project. (And ignoring all the public communications, e.g. blog posts complaining about the company not collaborating with the community, is work too.)