I have to say the reason I don't tank anymore is player commendations. I queue up for the roulette and say "Hello." at the start, if people have questions I answer them. Then at the end of the dungeon, the amount of player comms I get for signing up for a needed role? Zero.

This happened about 10 times one week, that pretty much sealed the deal for me. The gil/tome rewards aren't even close to providing an incentive to queue as a tank, I only went for the player comms, and since I can't even get that there is no point.