Ex-fucking-actly. Here's why this conversation exists in the first place: Superman, like all superheroes of his day, especially DC heroes (1938-1960's) was written for CHILDREN. Not middle aged men, not teenagers, CHILDREN. Pretty much every superhero had a code against killing because children were the target audience and largest consumers of comic books. But the middle aged men who now run the show demanded that their childhood entertainment grow up with them and now, unlike when I was a kid, you can't hand a child an issue of Superman, Batman, Wonder Woman, Flash, or Green Lantern because they're too violent for them. So now we have middle aged men who took superheroes away from children because they wanted more "mature" (and by "mature" I mean more violent) superhero comics getting their panties in a wad because someone took the approach they wanted and actually dealt with it in the morally grey area of adults. For some bizarre reason, this is where they try to make some kind of stand over some tiny element of nostalgia despite having upturned everything else. Yes, it was okay for every other hero to let go of the code against killing, but not Superman, no matter how powerful or maniacal the foe. It is patently ridiculous watching people say that Superman shouldn't have killed a guy who just mass murdered several thousand people and who was going to go on a killing spree with the choice being this: You'll have to kill me to prevent me from killing everyone else. Despite having a popular movie that hammered this theme over and over, apparently some people didn't get it: The needs of the many outweigh the needs of the one. They want the writers to present them with a cuddly situation where we don't ever have to face a situation like that so that they can pretend those situations would never exist in a world with super powered beings. Or they want the writers to make sure there's conveniently another option. They want a more "mature" superhero universe, but want the writers to make it just "mature" enough so that they don't have to feel embarrassed about reading about people in tights, but not too "mature" for them to have to deal with actual adult situations and the morally grey world that adults live in. Well too bad. Don't like it, then they should have let superheroes remain as the children's entertainment that it was meant to be. Where they could adhere to codes that were as unrealistic as the black and white worlds they inhabited. But hey, let's say Kal didn't kill Zod, what do these people think was going to happen? What was the body count in Metropolis? 5000? In a world where we executed Bin Ladin for a smaller body count and less property damage, what do these people think was going to happen to Zod? Here, I'll tell you: Zod would stand trial and be found guilty in the quickest open and shut trial in the history of the human race. Then he would be sentenced to death, and since humans have nothing that could do the job, who would that task fall to? Superman. That would probably be a pretty compelling story, but it would be too much for the people who can't see that Superman was in the right for killing a single person who just mass murdered thousands of human beings in order to prevent him from killing billions.