I think the older character being the villain may have something to do with the notion that many people become jaded and cynical as they age, and they're more idealistic (i.e. heroic) when they're young.
I just picked up another cliche, this one from a Sci-fi channel movie. Two bimbos challenge some idiot to something, while doing the dare, he gets killed by a huge monster. Bimbos run, but they stop BEFORE they're safe, the monster finds them, and one of them picks up a stick. A STICK! For, crying out loud, how dumb do they think females are?!
