Your on the right track OP...Sorta. Gaming forums in general are negative. When you give negative people a platform they will use it -- its human nature for complainers to want to be heard.
WoW has been out for 8 years and, as we all know, is very successful; however their forums are filled with vitriol and hatred and doomsayers. Again, give the .01% a chance to be heard, and they will scream.
Yes, I understand that there are haters on every videogame forum, no matter how good the game might be. However, there is always a faction of people who not only hate on the game, but they literally fear that the game they hate, could become the benchmark for future games of that genre.
Many people talk about how they believe story is getting in their way and how they hate how SWTOR is a game best enjoyed by leveling [experiencing the story] instead of more traditional MMO means. If SWTOR gets really big, developers could take note and future AAA MMOs could be more like SWTOR and less like the traditional MMO formula. So not only do they hate the game, but they fear the game's potential.