Obviously when you work for soemthing for a long time, the gratification is longer and also the time you feel good about it. But if you get things instantly, the gratification vanishes almost as fast as it came.
This is a natural human concept, and by making a game where you can buy things, they shortened its life span to make sure they dont have to keep the servers running.
However, they underestimated how fast their custoemers would get bored, and the expansion is coming to a game with too little potencial customers.
And this is why they are planing to change the game, to try to make it "interesting" again.
I wonder I people will fall for it. I certainly did not buy this game myself, after I heard about the auction house. Lets see if Blizzard gets a slap in their wallet for this.
After all, its the only thing they understand.