It sounds like you're doing your job well, it's the DPS' fault for pulling hate. This game isn't a DPS race as much as most MMO's and people haven't quite grasped that yet and unload everything to be the best, but it goes the opposite when they instead pull a lot of hate and make the run longer. I would say from what you've said you're doing everything right, but it's hard to say without seeing first hand.