As has been mentioned many times before I'm sure, the fundamental mistake they made with this iteration of the series is to basically mail the single player in and focus on multiplayer. I don't know about you guys, but playing the various stories has always been the big draw in TM for me (think of how great Black was in this regard), with multiplayer a distant second.
I completely disagree, focusing on multiplayer was the right thing to do. Can you honestly say that the stories in Twisted Metal were great? They were fun to watch, but that's not the reason you played Twisted Metal. Well, at least not the reason I played Twisted Metal. I play it for the crazy car combat, and in that sense it doesn't make a difference who is driving the car either.
Over a year later and I still enjoy Twisted Metal PS3 the same way I enjoy the others. I can easily set up an AI bot match on whatever map and loadout I want and have a blast, and I can get up to three friends locally to play a long. It's really no different than before, only now there was more of a focus on the actual cars and weapon designs.
You're entitled to your opinion, but I find it hard to imagine many people played any Twisted Metal mainly for the story and not for competing against their friends.