Based on everyones raging responses it seems that people are under the impression that Blizz is selling items from some unified vendor to the playerbase for money. These are PLAYER to PLAYER transactions. These sales would have gone on with or without the convenience of an AH.
Also - to call D3 an MMO is a bit misleading. Playing with 7 other people at the same time is hardly MASSIVE. I can't fathom how you get less fun out of an awesome game because some other guy is buying an item with his money - since he's too busy with his real life comittments to play the game.
It's like some sort of reverse elitism where people who may be unemployed or not smart or savvy enough to balance their gaming, social, and professional lives are raging out. Time is money. Game time is money - work time is money.