This is what i was thinking at first too. That the mobs aren't hard or do much damage they just take too long to kill. But now that I've leveled some and gotten better gear, when i go back to some of those same level 50+ mobs they aren't much different than pre expansion mobs. They die pretty quickly now. I imagine once I'm 60 with i180 gear there won't be much in the open world that will take more than 10 seconds to kill.