If you haven't watched MAN OF STEEL yet for whatever reason, you should probably turn away now as we will be dealing with some pretty big spoilers. Still with us? Good, lets go. MAN OF STEEL introduced us to a hero who was still trying to make sense of his powers as well as how to use them. When General Zod (Michael Shannon) and several other exiled Kryptonian's showed up to wreak havoc on Earth, Superman (Henry Cavill) was forced to take extreme measures to end the threat; namely, snapping General Zod's neck. Fan's protested this action as historically the man of steel has always gone to great lengths not to kill anyone.
Speaking with Nerdist (via ScreenRant), MAN OF STEEL writer David Goyer defended Superman's actions:
The way I work, the way Chris [Nolan] works, is you do what’s right for the story. That exists entirely separately from what fans should or shouldn’t think of that character. You have to do what’s right for the story. In that instance, this was a Superman who had only been Superman for like, a week. He wasn’t Superman as we think of him in the DC Comics…or even in a world that conceived of Superman existing. He’d only flown for the first time a few days before that. He’d never fought anyone that had super powers before. And so he’s going up against a guy who’s not only super-powered, but has been training since birth to use those super powers, who exists as a superhuman killing machine, who has stated, ‘I will never stop until I destroy all of humanity.’ If you take Superman out of it, what’s the right way to tell that story? I think the right way to tell that story is if you take this powered alien who says, ‘You can have your race back, but you have to kill your adopted race,’ the moral, horrible situation to be in is to actually be forced to kill, not wanting to, the only other person from your race. Take Superman aside, I think that’s the right way to tell that story.
As General Zod wasn't leaving Superman with much choice and Kal-El was obviously distraught with what he knew he had to do, I've never been all that bothered by Superman's actions. As David Goyer said above, this Superman is still dealing with the full extent of his powers and had he done nothing…there's no telling what Zod may have done before being subdued. It was a tough choice either way but as MAN OF STEEL is only the beginning of Superman's journey, I suspect that the Superman we're all familiar with will emerge as the character develops in future films.
Superman's next outing, BATMAN V SUPERMAN: DAWN OF JUSTICE opens on March 25, 2016.