As far as I can tell, the people who wrote the game's script have a pretty good idea of how people work. I've played many, many RPGs, and it's obvious that the complexity and variance of the characters has increased over time. We're a long way from days of "DarkSol wants to resurrect Dark Dragon for no apparent reason". Not that shallow characters are that unrealistic, of course. Many people really are that shallow. You don't think the people at the top of a brutal dictatorship have conceptual depth, do you?