I'll admit, when I first started I was bad about ignoring the marks and pulling aggro. Tho like I said I was new. I didn't understand the concept of pulling aggro, or how the entire process worked. I woke sleeping targets and just generally screwed the pooch as a dps. More than a few times I had healers refuse to heal, and tanks refuse to pull aggro off me. The only thing that reall accomplesed was puting me in a "screw them" mind set. Then I switched classes, went healer... Face palmed when I started to realize just what I had been doing. In truth players who don't learn early on will eventually become a drag sail for future dungeons unless they learn the hard way... But direct aggression is not a good stand to take, a simple explanation as to the why their method of play is hurting the group has far more impact, and this is coming from one of those bad players.