Sure, there's a lot of worthlessness floating around the forums, but that's why we have community reps that dig through it all. It's not just about looking for good ideas and solid reactions, it's about getting into the minds of players. Did anything even remotely tangible come out of our arguing about the bow-harp for 50 pages? Maybe not for us, but SE knows quite a bit about how we might react, what we're expecting, and what they should adjust to make it a bigger hit and a smoother transition.

Combined with the localization forums, which are probably the most useful and fun area of the site imho, I think the forums are working out just fine.

It's not SE's fault that MMORPG populations are mostly children and people with a lot of free-time, social awkwardness, and confrontation issues. That's who they're selling to, that's who they have to deal with. It's business.