Right. All might is morally grey? Naruto is morally grey? I can put out a list of villains who never got to have a point and was caricaturised .lex luthor is the only villain that got to have his point of view set forward. Look at Manchester black, heck! Even arion isn't allowed to have a point. This is why batman has more memorable modern day story lines.batman writer admits and allows the bad effects or limitations of his moral position to be confronted by batman.
Also, Kantian ethics itself is morally grey in this instance. Superman just chose 1 over 20. That is as grey as it gets. You know why it doesn't matter because it's an understandable dilemma.