Comes down to player being jerks or clueless OP. So many times i have seen dps attack enemies before tanks actually got to the enemy (Bards are real bad for this) and no Quelling Strikes.
However threat should not be all to hard to get back.
As for the comment about wearing dps gear, have you seen the current tank gear? It is utter junk, lol
When i do tank i have dps accesories and have not really had any problems holding threat.