I don't knjow about forum posts, but I think some of this comes from a reverse--and very weird!--issue that strikes me as "fanbois trolling in other games." Poor old Tabula Rasa had been out a few weeks when its general chat was effectively spam-killed by a handful of guys who spent their time bitching about every tiny issue and how it was either just like WoW or not enough like WoW. It was primarly aimed at trolling to get players who had, say, just bought and wanted to enjoy the game without reading a constant barrage of WoW love/Tab Ra hate going, and it certainly did that...I could only solve the issue by turning off general chat. So from that perspective, where many of the capitulations to the trolls were, in fact, "go back to WoW please," I can understand the problem.
Honestly, as a looooong time WoW player who feels that game has some playstyle and genre defining highlights that will affect the industry forever more, I can respect the problem people seem to run in to while playing other "less popular" MMOs in which a WoW fanboi comes onboard and basically starts trashing the game. I don't understand why they do it, other than for some malicious fun. These days, though, I am happy to say that I don't see any of that in DDO, the only other MMO I frequent anymore.
As for forum posts....well, I don't really like to hang out on forums much anymore except for Escapist....!!!! So I must plead ignorance on the matter, except that my guess has always been that the forum posters on MMO sites always seem to be disgruntled or have a chip on their shoulder for some reason....makes for terribly uninteresting reading, either way....