I've never been in a group that goes out of the way to wait for pats or hugs walls to avoid pulling. But clearing 100% of brd isn't better xp per hour than killing the 1 boss you need to get the bonus xp and reque.
DPS seem to think they're entitled to something because they had to wait in a que longer. Tanks think they're the leader and try to control the entire situation, and healers usually just follow and heal (mostly an afk job until about 80 anyway). My last monk, druid, and pally I leveled I was top dps, top heals, and top interrupt/cc. Does that make me the boss since I can solo most of the instance? No, but I think it has a lot more weight to it than a dps with full focus/rage/energy auto attacking mobs.
If the tank is doing his job well and wants to skip packs to increase his xp per hour, by all means he's entitled to. If you're doing any good he'll probably share his instant que with you and increase your xp per hour. If you ask nicely to kill an extra mob for a quest or a little more exp to help you level, he'll most likely do it. The problem is the kids who think they're God and pull everything because they hate sitting in ques, then they don't roll on greens so you perpetually can't kick them from the dungeon. That's why tanks get angry.