Maybe it's rose-colored goggles, but it seems like the forums have gotten worse since WotLK.
BC brought us the arena elitists. Say anything: "lol @ ur rating." But honestly, they almost had a point. Sure arenas were horribly unbalanced and generally awful (I say "were" because I've done none in WotLK so I can't honestly say "are"), but there was some slight correlation between skill/knowledge and arena ratings.
WotLK has brought us... just general assholes. There's nothing even specific. Well, in general it's something about raids being too easy. This will lead to a tangent later on. In the meantime, why?
I think it's because raids really are a bit easier now. With the exception of Razuvious, none of them really demand a certain class. This isn't actually easier, it's just more accessible. Consumables are lower than ever: oils and stones are gone, self weapon buffs are good now.* Again, accessibility: you don't have to play so long to prepare for raids. Fights seem tuned a bit easier than I remember from Karazhan, though I wonder how much of that was due to fights like Moroes having unreasonable expectations, such as priests keeping up a shackle and hunters not going afk with autoshot.
What happens when you make content easier? More people clear it. If your ego is based on a sense of virtual superiority, this is bad. BAD. The reaction is not surprising in this context: people lash out when their superiority is threatened. Yell at Blizzard: "How dare you let... let... those noobs! In my instance! The nerve! Why am I not obviously better than everyone else!?" Remember recolored tier sets for PvP? Repeat, except bigger.
I think what really makes it funny is that the raids actually aren't easier. The major challenges just became optional, in other words, stopped giving gear. Achievements don't give gear (I'm excluding Sarth bonus gear because I don't like facts which do not support my claims), but they're where you'll find the hard stuff. The new approach to gear is strange. It seems that everyone gets it now. Before you blame it on noobs and their sense of entitlement, it's the self-declared good players who are confused at the lack of gear rewards for their superiority. "I am awesome, why do I not get to one-shot people because of this?"
I've also noticed a very annoying trend of bad players claiming to be casuals. Casual is not bad. Bad is not casual. Casual is hard to define, but let's go with something related to play time or the relative priority/importance of WoW in one's life. Bad is... bad. The hunter that uses strength gear is bad. The paladin with spirit gems is bad, well, maybe not as much as the hunter. Spirit is a deceptive stat if you don't read too closely the little "while casting vs. while not casting." Really, it's annoying to see people be stupid and then claim that they're casuals so they don't have time to figure these things out. Min-maxing and basic class knowledge are very different.
Casual players, I'm sorry that bad people are trying to hide among you.
For the good of everyone, new players should not be allowed to post on the forums, at least until they've played for a month. For them, it saves them the terribleness of the forums and the assholes within. For other people, it acts as a filtering system. Sometimes I see a 'stupid' question and think: "Is that person an idiot or are they just making the same mistakes I made early on?" If we kept out the new people we could be certain that only true idiots were posting stupidly.
To compensate for the loss of community support for new players (please bear with me, I am trying just as hard to not laugh), add official, Blizzard-created basic starting guides. Maybe the tips do this, I turned them off a long time ago. It wouldn't be too complex, just things like useful stats, groups roles, and the concept of aggro. If someone could figure out a non-condescending way to say it, include something like "think things over and see what you can figure out for yourself." For example: think about strength vs. AP. Hm, strength gives AP, but strength is affected by divine strength and blessing of kings. However I'm leveling so I'm not likely to see either talent. I'll go with whichever I see more of, with a 1:2 ratio.
Or there could be a newb-only forum, just for new people, with a few Blizzard-approved posters. They'd be like the greens (MVPs), but more useful.
I wish people were a bit less afraid in-game. I love giving people advice. It makes me feel all warm and superior inside. Why do people so rarely ask questions? At most: "what does this boss do?" Rarely do I see people ask others of the same class for advice when they clearly need it. Slightly less rarely do I see people offer advice, and that's including rude criticism as advice.
* I played my warlock a little bit and was trying to figure out a demo spec for leveling, since I like the bit of durability, especially being on a PvP server, I want to minimize my risk of sudden death. I ended up staring at the wowhead calculator trying to figure out why master conjuror was my only choice. Then I looked up firestones and spellstones and... wow. They don't suck anymore! I still don't know if the talent is good, but at least the conjured items are useful.
Today I showed a shaman earthliving weapon. He was using flametongue. The death rate dropped a bit after that. His spec was very strange: enough resto to DPS badly and enough elemental to heal badly. I didn't get the point. Perhaps I should have helped, after that little bit about why don't we help each other.
In unrelated news, I got annoyed at a warlock who didn't have shards to summon me back to an instance. Why did I leave? I needed to go buy ankhs.