wow, you really have it in for gaming on Linux. Steam has absolutely made Linux a 'viable' gaming OS if it wasn't already. SteamOS is doing great things too.
None of the games I play are available on Linux, none of the new AAA titles are available on Linux. With Valve not fully supporting SteamVR on Linux currently through the HTC Vive that's not even an option either.
But the difference is that I don't have some bias and will not attempt to fool anyone by portraying that they can use Linux or SteamOS as a gaming setup, not unless they only play the few 1st party Valve games, bargain bin AAA titles and Indies because beyond that it's very slim pickens.
Gaming sounds of primary concern to you, for others they want the development environment and freedom of Linux and gaming is a very pleasant bonus.
You say you don't have a bias and then finish off by saying you are biased against Linux because it only has certain games. You only like games that are "great" because they hold an imaginary title of AAA.
I admit I am biased towards gaming on Linux. The main reason being I don't like being forced to purchase and upgrade to a slightly different OS to receive the "best" gaming experience. A gaming experience that can be had on the older systems but is deliberately crippled by the software. Hooray for Direct X!