I'm a Linux guy. I've had it on all my computers since I can remember, use it at work, and even got my wife using it. However, recently I wanted to play a new game (Starcraft 2) and the support on the most "friendly" distributions (Ubuntu and Mint) were shotty at best. Sound problems, video inconsistencies, you name it there were problems. Emulation (with WINE) is buggy and virtual machines introduce a performance bottleneck.
Until games companies support Linux or vice-versa, the Linux desktop will not be used by a large segment of computer enthusiasts: gamers.