The problem with 4 man dungeons is that you can't give them higher tier loot than Coil or Tome gear, because that'd be ridiculous but at the same time if you don't give them good loot but make them difficult they become even more of a tedium to run. Restricting the rate at which people gear through the lock-outs is a very conscious design decision on their part, and 4 mans just being huge trash pulls and face-roll bosses is the consequence. They've basically created a system where it's impossible for them to be relevant other than as a vehicle with which to get gear that is independent from what is actually obtained in the instance.