I liked it in Conan the Barbarian. The bad guys killed his parents. Now it's revenge time.
Maybe from the games you have played they are crap, but that doesn't mean that there aren't any good ABS's around.
Examples:
http://www.youtube.com/watch?gl=GB&hl=en-GB&v=tiKdUJx42DQ&feature=related
http://www.youtube.com/watch?v=qmnD-4dYZkY&feature=related
http://www.youtube.com/watch?v=f7SotgdE824
I like that idea too, but I think it would be a cool extension to the idea if the player didn't know they were being tested - ie put them in a situation that requires them to make decisions (not literal ones) and then come up with an algorithm that suggests a class for them. If I were to implement something like this I might not even tell the player that any of the above happened, nor make it known they're even in a class based game.