there were the constant server issues, the missing features, and i'm certain there are other things i'm forgetting. but vicarious visions is currently best known for their awesome tony hawk pro-skater remaster which was their last release before being merged into blizzard. there's no proof of course, but i think blizzard somehow corrupted vicarious. a studio doesn't just go from what many consider a masterpiece to something just scraping the barrel for playable.