Agree with the OP, reason DH is such a mess is because people don't clear the dungeon they just train it.

Good example is the guy above who said the most rewarding aspect of the game was a speed run through DH and yet that involved ignoring the majority of the trash mobs and zerging the bosses with archers, nothing rewarding about that IMO.

Personally I think for DH they should remove the actual dungeon timer and only make bosses pop after you have cleared the area of monsters, then have the actually boss have an enrage timer.