Why I don't Q as tank for DF anymore:

Healers and DPS that pull ahead.
DPS and Healers that don't use aggro mitigation tools and then being told that they shouldn't have to because it's not their job.
Healers that don't DPS
DPS that can't actually DPS
Healers that can't heal
Tanks that fight for aggro because they're afraid to turn off their tank stance when they don't need to hold the boss.
Popping into a party in progress and having everyone shit on me because they didn't like their last tank who rage quit on them (at this point, I leave too).

I love tanking. It's really fun. But I'm not going to spend 30 minutes with people to get shit on. So... maybe if that were to change, you'd get more tanks and more tanks running queues. Until then... GLHF