The main issue is that it feels like the game was designed to support the auction house, and not the []
The main issue is that it feels like the game was designed to support the auction house, and not the other way around. Almost all of the fun of these games comes from steadily improving your character and gear, and occasionally lucking out with a world-beating drop. Since there is no statistical difference at a given level between one character or another, and the skill combinations are fixed, they've effectively removed character development as a motivation. Also, I find that it's exceedingly rare to get a drop that I can actually use, and since items better than what you have can always be found at the AH at rock-bottom prices, you essentially short-circuit the entire gear improvement process. Since the game's story really isn't up to the level of the other ones, there's really no reason to keep playing other than enjoyment of the mechanics.
