I think a lot of the issues are that it's boring to tank. You do lackluster Damage, and your always fighting the same enemies. No tank ever needs to learn anything new in the new dungeons, because they're tuned for ilvl 55 still..

If Square made dungeons engage the tanks more, it would be a more fun job to play. When the Enmity buff was put up, I lost a lot of what made the job fun, because now I can hold enmity on both jobs in my sleep. Tanking is BORING.