I fail to see why that even matters. It's not like you have to know how to play your job to get to 50 in this game... That being said, just take note of who they are, and don't invite them again. Or! God forbid, explain things to them and help them out. Unless they are the arrogant kind that don't take constructive criticism without turning into a troll.

All you need to tell them:
1. Only attack red mob.
2. Press 1 over and over.
3. ???
4. Profit.