This is because hardware manufacturers don't upstream drivers.
Or, for that matter, one that I can use for gaming.
What are you talking about? I've been gaming exclusively on Linux distros (Ubuntu, Fedora, SteamOS and Solus) for the last few years and it's been great. Site/community gamingonlinux.com is a testament to Linux gaming being a viable platform.
The sad truth is that some great titles only run on Windows.
If no one writes game for any given platform, is it the platform's fault? Network effect don't explain everything, but they do explain a lot.
There is more than 3000 games on Linux on Steam right now. A lot of it is indie, but still thats a lot of games.
i have used at least 4 different distros for gaming so I have no idea what your comment is supposed to be about.