I don't see what's wrong with running past mobs to get to the certain areas.

Because there are certain choke-points where you have to fight some mobs. Also, it takes a lot of coordination to run past them if you're in a PUG or something.

The main problem is that it's too easy to get to the 1st and 2nd chest and get the best drops. And you can just rerun the dungeon 39812312 times to get the best items. So it seems like an exploit.