You might not have the mentality of maximizing DPS, but the tanks who do so happen to speed up the dungeon. You don't have to do it right off the bats, but just consider that there is such a thing as TOO MUCH enmity.

For example, when you're fighting the dungeon bosses, you don't just spam your enmity combo. That would be an example of a tank who couldn't care less about their damage. Doing that takes 0 effort, and yet guarantees the boss will stay focused on them. However, why would you do that, when there are other skills you could be using and STILL keep the boss on you?

Figuring out where and how you can squeeze in that extra bit of damage is what "maximizing DPS" is really about, and honestly it's part of the fun of playing a tank. It was never about doing as much damage as the DPS classes.