what's the point of nerfing when AH is gone?
Longevity. A large portion of D3 players play specifically to max out loot and once they have maxed it out they no longer have reason to play.
Its easier to make a game designed around manipulating the brains reward system with loot then it is to create fun gameplay.
Not saying the game isn't fun.....its just by closing the environment they have limited D3 game mode possibilities and IMO the play modes they currently have are very limited.
If I were the D3 director I'd put most of my focus on game modes. Tower Defense, None stop mobs, Time Challenge, PVP, DoTA, Team VS Team, custom map creation ect.
My secondary focus would be on statistics. When in a multiplayer game its would calculate tons of stuff like damage dealt, mitigated damage, Kills, and give out cool titles when completing a rift like Slayer for the person who killed the most, Do you even lift for the tank, fragile don't break for the least damage taken.
.....but its far easier to limit gear to focus on the loot grind.