Almost all major online multiplayer games are set up to run either mac (apple) or microsoft as a choice for software.
Literally NONE of them are set up for Linux, oh the developers LOVE unix/linux software and use it for themselves and to some extent to write the codes for the other two, how, I don't know, but I have been in chats with a few of them.
Steam is a launching platform and converts a game to what ever system you use.
A lot of the "heavy graphic" games won't work with steam, it causes video lag and game play is decreased. In a player vrs. player environment frame rate and connection rate is paramount, or you die.
I am currently thinking of buying a "used" laptop to play with the Linux side (my little asus is now a security system), I remember using Linux to log into my battlenet account for one of my games without using "wine", or so I think I did. Something about searching the windows side of the hard drive file system and "attaching" the .exe file to the desktop or some such (my memory sux).
I might use my wife's little asus to experiment with.... well, maybe, if she lets me
I purchased a little rca tablet for her to take when she goes out, so she rarely uses her asus now. I will just dual boot it like I had on my asus and go from there.
Back on point.....
When it comes to gaming, windows is king at the moment, developers are hating the fact that they might actually have to listen to thier customers and re-write their software to include yet "another" operating system spec.
However, with the open source, it could get tricky, because a lot of folks use "third party" software to "add on" to a game to enhance it for ease of use gaming. The add-on software lets them do things the original game was not designed to do, like map coordinates, memorize path of player through an area, location of treasure memory, ect.... Most companies allow it, only if the developer submits the code to the company for approval, and a third OS would mean more company man power to search codes for bad things....
Ok, now throw Android into the picture....I don't even know how to class it... Google?
So then you would have four different software setups per game.... I'm not sure developers would go for that.
And due to the popularity of the Android software, I would think Linux would be pushed to the side and Android would be the next to step into the gaming OS software alliance, but, it hasn't been turned into a PC software yet......
So the gaming delema for me is this.... I HAVE to stick with Microsoft, Apple computers are OVERPRICED and not affordable to me. Android has yet to step into the PC arena as a viable gaming system software. The major gaming industry will not consider even writing game software until sales show a distinct rise and 100's of thousands of gamers are online with that OS and complaining to have the games in Android versions.