It's no secret that even after the move to the new digs, the forums can be kind of a rough place. Part of it can be the "squeaky wheel" phenomenon, of course. People don't often stop and make posts on a forum when they're happy about how something is going. Still, it can be a bit of a slog to get through sometimes. Nethaera wants you to get as much out of the forums as possible, however.
Some of the suggestions made seem obvious (read the terms of service and forum guidelines, for instance), but a lot of posts get closed for being off topic or extraneous, so it's probably helpful to go over them again. It's probably also fair to say that some of Neth's points fall under the category of "common sense," or what some folks call Wheaton's Law.
Frankly, I'm somewhat disappointed that after more than 15 years of internet, we still can't get a handle on this basic idea. There's a level of civility required in discourse in order for it to be discourse. It's why people like Samuel Johnson and Oscar Wilde are so widely regarded for their wit, because they could insult you to your face in a civil manner and you'd have to give it to them that they did a good job. If you can't be nice, you need to at least be clever enough that it's worth reading.
The point of the forums is to provide a public space for WoW players. If you're not actually interested in making use of a public space but are just there to fling excretions about metaphorically, save yourself the effort. Let people who do want to use them do so without you making it harder for them for no real purpose. Neth's followup post in the thread is useful reading on the issue of what Blizzard actually does on the forums.
What ultimately comes out of all this is what the forums are not, which is to say they are not a panacea to all ills you may have in the game. Posting a problem to the forums does mean it has a reasonably high chance of being seen by Blizzard, especially if it's in an existing thread so that thread becomes more notable, but it is unrealistic to expect immediate action simply because a post was made. You will have to accept that it will take time for things to go beyond the reading stage.
Forums are a public space for the exchange of information both between Blizzard and players and between the players themselves. That's a big job as it stands. If clogged up with diatribes and insults, they can't do that job, and they can't do another job like serve as a magical wall upon which your heart's desires can be inscribed and immediately fulfilled.
World of Warcraft: Cataclysm has destroyed Azeroth as we know it; nothing is the same! In WoW Insider's Guide to Cataclysm, you can find out everything you need to know about WoW's third expansion, from leveling up a new goblin or worgen to breaking news and strategies on endgame play.