the alternative OS folks do have a vested interest
There is probably some affect from the vested interests of alternative OS folks. These days games are published for the Windows/DirectX combination. Many folks would happily buy games for alternative OS if they where available. I'd personally love to have Dragon Age native under Debian. It would save me stopping everything I'm doing including background VMs just to reboot to Windows; which only really exists against hardware on my machine for running video games.
I'm sure some of the affect your seeing is from gamers saying "hey, we have wallets and play video games too even if we don't us Windows primarily. Stop forcing the OS choice on us and we'll happily buy your games."
Us non-MS gamers have money too. And usually more of it when not extorted for the Windows license fee. Nvidia, good job so far but polish up those drivers and deliver dual-header support like you do in the Windows driver. Game companies, ship *nix native games and put a little help into OpenGL and related frameworks to replace DirectX (on Windows as well as off) with something you can all benefit from; a truly cross-platform game framework.
