I think the point of comic book lore and superheroes in general is to present us with pure good vs. pure evil, even though we know it doesn't exist in society. If it were meant to mimic reality exactly, the Dark Knight would have just been a straight drama. But it's supposed to have that epic element to it, because people want to believe that the battle exists pure good vs. pure evil and that pure good can win. We might know it's only a fantasy, but when we go to movies, we're allowed to suspend reality for a little while. I think that's the point, rather than trying to present the points they are making as novel ideas. More of an examination than a treatise.