The thing is, information leaks. You can go and read the Windows source code, if you want to, you just would get busted if you actually use it to build your own Windows or something.

Likewise source code is a shared a lot in my experience, i.e. the important software that's closed but has the important customer, the important customer gets the access when they ask for it. This depends on who you are and what you sell, of course.

So in practice, the difference isn't that huge.

That said, you are right too, THERE IS a difference. And it's better than entirely closed source.

So I will prefer the source-available over completely-closed-source, but I'm not going to be grateful about it.

And then there's realities, if I'm writing business critical software that my life depends on, I'll make it closed source in all likelihood. I'm not Stallman.

So I don't blame anyone for caring about their interests, it's entirely fair.