Originally Posted by
Kisho
Judging by this post and your many prior posts, I'm almost 100% certain that you'll come across as an elitist jackass when you try to tell them how to play.
You will not, ever, change other people, especially not ones who you meet in random 5 man dungeons and never see again. They have no reason or desire to listen to some random guy who is probably throwing thinly veiled insults at them in the guise of 'advice'. So there's only one viable option: if you can't change them, change yourself.
Stop giving a fuck about how much DPS is being done. MoP heroics are ridiculously easy, especially now that people are getting raid geared. Who cares if someone is doing low DPS? Are you still clearing the place? Probably, so just deal with it and move on.
Getting angry/upset over this will solve absolutely nothing, and if you are doing what I said above (acting like an elitist jerk when 'giving advice'), then all you're doing is ruining the moods of the people in the group with you as well as your own. That sounds like a net loss to me.
You can't change other people. Change yourself: stop getting upset over the low performance of the other people in the group. So long as the place is still getting cleared, then there's no issues whatsoever.