One thing that's always bugged me about Warcraft: there's two different games. There's the questing / levelling game, and then there's the raiding game. Both are great games but play quite differently, requiring different skills, gear, talent specs, and temperaments.
But most importantly they require different size groups. Raids require 25 (or 10, or 40) people, questing is best done alone. I keep trying to do quests with other people but everyone moves at a different pace and everyone's done different quests. Unless you make a firm commitment to quest perfectly in sync it's easier just to go solo.
Except for the healers, who have a hard time questing solo. I feel bad. Every hour or so someone will say in guild chat "Healer LFG" and I selfishly ignore it, too busy in my own solo activities. I should be helping them, goodness knows they help me enough.
Then again I'm hardly questing myself; I'm too busy exploring and levelling professions. I'm only halfway through level 71. Need to buckle down.