If the tank dies, it's the healers fault.
If dps die, it's the healers fault.
If the healer dies, it's the healers fault.

I've come to expect this attitude from most DF groups. Luckily, I don't use DF much.

I went to help in storymode Garuda one time and the dps that was with us wouldn't move behind the rocks.
His reason was that I could just rez him if he died so it didn't matter if he took damage.

Easy way to solve this is to just stop healing them.
They soon learns that they get my heals if they're a proper part of the team and do what they're supposed to.
Sure, they kick and scream and call you a noob, but they'll move from an aoe the next time one appears