I honestly think it's the other way around: the "great community, btw", gets a ten foot erection for popular streamer and start having ridiculous expectations that they promote their chosen game. Yeah, there are retards like Pyromancer who do have a melty, but they also aren't anywhere near as big as someone like Asmongold is in terms of sub numbers.
Asmon would be king shit if he stuck with XIV. The reaction shot of him coming out of the first cinematic (or whatever) to like a football stadium parking lot of that FFXV car lined up to him was more or less proof of that, IMO.
I just don't think he likes the general aesthetic or vibe of the game, but knows that playing it draws in viewers. It's a bit different from Dark Souls, where he was getting dummied and he took a break cos he was getting frustrated (I think, I'm not an avid Asmongold viewer but I catch flare ups here and there on livestreamfails.)
I also don't think that XIV is all that particularly engaging streaming content, to be perfectly frank. You blow your load with the MSQ and 'reacting' to the 'amazing' story, maybe do a few raids and that's about it.