You know, in Batman Begins, nobody ever said, "Hey, this is supposed to be Bruce Wayne's first time as Batman. Why doesn't he suck? He should suck since it's his first time!" So I don't see why Superman being lousy at being super gets a pass. Yeah, maybe they can have him not be as up to it earlier in the movie, but once you get to the final battle of the origin story, he needs to come full circle and truly BE Superman. So to me, that argument holds no water.