As a home Linux user I am always justifying my OS choice to friends and whether its “I don’t really play games any more” or “It does everything I need it to and I don’t need to worry about continual computer upgrades” but with the recent announcement that steam is coming to Linux it may not be an issue any more.
If games are developed for Linux it will hopefully push the Graphics drivers to a place where they do the same as any other platform, at that point the difference between Linux and Windows as a home desktop closes closer than ever before.
So the big question now is why don’t more people use Linux of some flavour.
The biggest reason is still that the OEM market is still almost 100% Windows and most people feel uncomfortable with fresh installs on a new PC however more organisations are attempting to make their hardware last longer and on this side Linux is normally a good option. As Gnome, KDE and Unity have all steadily improved their user experience the amount of retraining has decreased and with Libre and Open office offering more and more support there is little difference.
Promotion of distributions is the key to any mass acceptance and Ubuntu has done a reasonably good job on this front that when people think of a Linux Desktop they think Ubuntu so what is stopping the others? This I have no idea about other than perhaps they are still more focused on the server market than the desktop one but hopefully with games on Linux we will finally see a move towards this as a marketable option.