THIS! Superman in the comic books and in the movies lacks alot of depth. There could just be so much more to him and his character but he's just kind of there. Batman is more complex as a character with more emphasis on his moral values, why he is the way he is, his hurting people but never wanting to kill anyone etc. It just makes you more invested in the character.
Snyder has awesome graphics and can tell a somewhat cool story, but it just in the end tends to be a sloppy story line, but pretty to look at. His characters often contradict themselves and their own values in his films and it's never explained why. It just "is".