The DM is a person too, so their fun does not trump the fun of the group. If we must submerge the I in the We, then it doesn't matter how much work the DM puts in. They are merely one more part of the Collective.
Agree 100%. But that still doesn't mean that the players make campaign or rules decisions. They make decisions for their own PC. Not someone else's PC, not the NPCs, not how the world is set up.