Good point! Superheroes are in a way his offspring. Villains are different, they're always there to assist and represent the heroes. It's what keep them busy and heroic. Now, the villains of Superman are very different. In order for them to achive their goals they had to make Superman weaker than he really is...it explains why Superman never destroyed Darkseid or the others having kryptonite as his only weakness. For movies you'll have to dig deeper.