My 2 cents...
I think it's due to changed personalities. Bunch of lame idiots on here who go around desperately searching for opportunities to call repost or find some other way to utterly humiliate and degrade the poster above them while not having the guts to post something of any use to us real people.
Also, Hot Deals used to be the main draw, and now there's a bumber crop of similar sites and most of the Hot Deals are simply what people picked up over at Fatwallet or something.
Bottom line - AT is awesome and the posters have just faded.