He has no choice but to grind dungeons, he said it multiple times he does not find farming dungeons fun at all but it's something that he has no say in. The moment he steps outside the dungeon to try to do literally anything, a swarm of Horde comes to try to gank him, just look at what happened when he tried to get Whirlwind Axe, even 200 Alliance wasn't enough to protect him for a single quest. And this isn't unique to Asmon, but to all big streamers which is why most of them are only ever doing dungeons, besides farming dungeons with a group is the most efficient way of leveling besides being a mage and aoe farming mobs in the world, and they're all going for efficiency.