KOTOR2, although IMO not as good as the first, was not a bad game. However, it was an extremely unfinished and buggy one. Some of the ideas and gameplay enhancements it had could have made it a better game than the first, if they were properly implimented and complimented by a complete story.
This was most likely because Lucasarts rushed the game to meet the holiday deadline. Also, early the next year, MArch I believe, Jade Empire was being released and LA did not want their game competing with Bioware's next game.