why would they bother when they dont officially support linux? it's just gonna be additional cost for them so support something < 10% of the install baseWindows = 81.77%OS X = 13.49%Unknown = 1.97%Linux = 1.68%Chrome OS = 1.08%FreeBSD = 0% The numbers are based on a subsection of web sites, so I wouldn't use those for looking how big market share an OS has, then it would be better to look at Humblebundle and Steam to see a more proper numbers, but do not forget that there are far more games for MS-Windows than for Linux or MacOS which can have some impact on the numbers. In the gaming sector Linux is on it's climb, at Steam they will soon have a market share over 1% and at Humblebundle when there are Linux version of the games the market share is closer to 10% (if I remember it right) and they do pay more for the games than MS-Windows users do. They can do things a lot better, use Vulkan and keep as much of the game as possible platform independent, this would lower the cost to port things for other operating systems, sure you have to do a bit more in the beginning, but with little effort you suddenly could have at least 3 OS:es on one architecture covered, but sure money from M$ will always be interesting for some companies, so they will stick with yesterdays technology. No matter what ANet does, there is some serious issues in their code which they need to sort out unless they want to loose players.
