When I'm on WAR or PLD I rarely need a healer in 81-90 dungeons, they are there just to be my cheerleaders. I need some healer maintenance on GNB but nothing serious, DRK on the other hand...
If you honestly think that DRKs current kit in regards to mitigation and sustain is equal to the other tanks in dungeons, you are delusional and need to lay off the copium.

Leveling WAR, PLD, and GNB in the new dungeons has been the most fun I've had on leveling tanks in any expac, meanwhile DRK was a complete nightmare. It has nothing to do with player skill, how can a formula 1 racer compete if instead of their vehicle they have to race in a go cart? DRKs that don't recognize the issues with their job either afk too much in limsa or are being carried by very patient people.

I main healers, especially SGE, and I love the challenge of healing a DRK but I will not think less of other healers that don't wan to deal with that mess.