The idea that healers don't DPS is weird to me, but maybe that's because when I queue for something I always intend to give it my all. By that I mean, all of my attention and all of my effort. That's just how I am.

Why wouldn't I DPS when on a healer role instead of just standing around? Obviously if it's dangerous to do so for whatever reason I'd focus on healing. But, I mean, generally you'd want a run to go faster rather than slower, right? Also, you'd want to actually play the game, right? I wouldn't find a game fun if I just AFK'd and let my fairy heal a dungeon, or just stood around waiting for someone to take damage. I want to help my party succeed.