I go into DR as a tank a lot. I always use tank stance knowing well enough im at the mercy of glare/broil/maleficmages with profane essences ....
Going in with essences and some lost actions results in me doing more dps then 66% of the group.
Depending on essences used tank dps can be damn high. So dont go tell tank dps doesnt matter.
Also if those tanks use irregular essence, i understand they dont want to tank.