I can see the complaint but it's not necessarily a FPS thing, just a can you sit down for 4+ hours and be focused the entire time on a video game. In a mmo you don't have to when raiding, sure the raid might take a while but there's a fuckton of lulls, like between pulls, after wipes, before pulling a boss, waiting on afk people that kind of shit, plus in general unless it's high end raiding it's not even that stressful because the difficulty is fairly low and that's especially true on farm days and shit. On the other hand if you play 4 hours of a FPS, chances are you're actually playing the 4hours, not playing 2hours with constant breaks. Holds true for almost every game but RPGs which tend to also have a lot of "lows" in the action, like cutscenes and dialogues and what not.
Not that I'm personally affected, but there's a clear difference between the required activity to raid in a typical mmo vs playing more action oriented games.
