Linux userspace is defined by fragmentation. Linux users can't even unify on a distro, such that significant swathes of software are incompatible for some users despite everyone using the same kernel. In that environment, and also just in general, why is anybody obligated to contribute to a specific existing project rather than building their own?

Compiling their own tool for linux (ie advancing cross-platform support) is not "fragmentation".

Fellas, is it fragmentation to natively support linux?

If you see it form the point of view of a Linux user it's more fragmentation, but if you look at it from the point of view of a gamer it's less fragmentation. Guess who their target audience is?

Fragmentation is a good thing, it's called competition, and user choice. If you don't like it, buy a Mac or something.

Everyone in the linux world insists on fragmentation, though? It's a part of what makes it great and a mess at the same time.

And what of it? Every time a for profit company uses open source they'll either create a closed fork, and if they can't they'll create closed source modules for it.

I'm not saying it's bad to wish for companies to support FOSS, I'm just saying it's an unrealistic expectation to have.

Why would they join another project that's worse than their own solution, over which they have full controll?