In that arms race personality and motives were largely forgotten. Today things are supposed to be different. Most modern RPGs devote more space to background and motives than any other facet of the game. Perhaps this isn't surprising. She was a useless bimbo anyway, kept getting kidnapped.
Disadvantages sometimes work well, but like any other rules system can be abused.
Another common idea, which avoids some of these problems, is to ask the players to write about their characters' background and experiences, goals, and personality, without any immediate effect on the actual game mechanics. This at least encourages a little thought, although taken to extremes of psychobabble it can get a little silly. In Vampire and its sequels, and in the Amber RPG, it is possible to spend several hours discussing and acting out the history of characters before play even begins. An interesting approach to this idea was used for the fantasy game Everway, recently remaindered extensively. Players each pick a few cards, combining their themes and these questions, to create the character's story.