I don't think you can really put all the blame on the warriors. Whenever I get random tanks, or even some in my fc who queue with me, they'll put on shield oath or grit regardless of whether I have defiance or deliverance on. Besides, a lot of the tanks I see stack parry to high heaven and refuse to leave tank stance claiming, "I'm a tank, it's not my job to do damage." And then the others just try to dps with little regard to the other 7 people in the party.

Df...amirite