First off let me say that I am actually a firm supporter of the LFD and lately the LFR mechanisms. For a long time I was a guildless, friendless adventurer with limited play time available. Being able to queue up and jump into a dungeon kept me playing the game. I do however have to acknowledge that it did have some negative consequences. Not least of which it seems to empower the worst among us to behave poorly.
I recently had the "pleasure" of healing a paladin tank who was tanking BRD with no shield. This would possibly be OK if he was using a two hander in ret spec, but no, he was using a intellect off hand?? What?
A little later I was in a dungeon with my hunter, 2 DKs and a holy paladin. The DK tank died or came close to dying quite a few times. The DK DPS was ranting at the healer for consistantly calling for mana breaks, and then running off and pulling. The tank wasn't holding aggro at all. At this point I thought I'd have a look at what was going on. Both DKs were unholy specced. And the "tank" wasn't even in blood presence. There were so many easy to fix issues, but rather than stop for 2 minutes and sort them out everyone was trying to gogogo regardless. Take a breath people and try and improve... even slightly.