All the 'new' areas are stolen from past Infinity Engine games (Bg1, Icewind Dale, Planescape: Torment).
You're being a bit unfair, here--it's like accusing a bank of hoarding money.
I'm no spokesperson for TeamBG (thanks the gods, since their team leader has all the person skills, judging from his posts elsewhere, of a gila monster), but they said right from the start that they would be using (with Interplay's permission) the background art of previous Interplay CRPGs. It saved time, and let 'em spend their efforts on coding quests, etc.
Buggier than the lovechild of Daikatana and PoR.
Have you played it since the 1.02 patch? It's much better.