The reason why Superman movies are hard to make is because its hard to put together a story when the protagonist is unstoppable. Easier to do in books and comics, hard to do in a 2hour movie. You get like what, 25-35 minutes to set things up? Then the conflict, then the end. Hard to make an antagonist look like he can really be a challenge for someone like Superman. Unless you choose someone that is also fucking powerful for him to fight and just go fucking dragon ball z crazy.