Far as I'm aware, Blizzard's "support" for Linux doesn't really extend any further than some effort to have Warden play nice with Wine so people can play and not get banned (and I'm not sure how much of the work is from each side ...).

I'm actually surprised it is not becoming more popular - with so much of the Western economy as it is, and so many computers not coming with Windows media in case of disaster (pretty much you either have to use the clunky recovery method provided by the manufacturer, which often requires stuff on the hard drive to be intact, which is often not the case during a disaster, or you have to just shell out the 120 USD for a normal copy of Win8.1); not to mention all the older computers still in use that will need upgrades (or should already have had them in the case of that chunk running XP!) for which Linux is likely much more suitable than 8.1 (then again, these computers probably won't run FFXIV well anyway ...).