Steam developed for Linux a while back but stopped. There’s a push toward Linux for desktops with major OEMs, and I think this is becoming a sell point for gamers. I’ve been on Ubuntu for years and love it. I use Fedora for my home servers.
I still have a Win7 machine for gaming, but most of my day-to-day is on Linux.
Anyway, like you, most of my day-to-day in on Linux, but of the 7 to 12 computers on the local network, only three that I personally claim are running linux (ancient screenless laptop as mail and print server, some old K8 machine in a desktop case as file / photo / music repository and server, and I do most of my keyboarding and viewing on a $150 NC6000 from ebay). The other machines are WinXP or Android (close to linux) or iPods.