I couldn't disagree more. Thematically, the game is very deep. KOTOR:1 had a nice twist, but lacked any depth. Malak was a cardboard cutout villian, and never once in the game did I feel like I was playing anything other than a black-and-white simplistic story.
KOTOR:2 really digs deep down and explores the roots of whether or not violence is ever justified. Were the Jedi right to avoid getting involved in the Mandalorian Wars? Was the Exile right for disobeying them? Is it possible to fight for what is right and not be affected by the ammount of violence, death and suffering surrounding you?
Futhermore, instead of a cookie-cutter villian, you have symbols of hunger, pain and betrayal. The Sith became more than silly bullies. The 3 Sith Lords weren't executed perfectly, but from a theme standpoint, there certainly was far more to the story.