>>149875910
>but not when almost every other comic book hero implicitly employs the exact same rule?
Batman is willing to kill or nearly kill other people to stop them from killing villains even if they've murdered millions or there is a personal grudge involved.

Superman would never use his fucking heat vision to sever the neck arteries of a cop about to shoot the Joker. Wonder Woman is explicitly the most kind and loving and diplomacy focused Trinity member but she also understands some threats to peace can only be resolved with force, she always offers an open hand before a closed fist but when it's time to draw her sword she doesn't hesitate.
Batman's no-kill rule isn't just a personal code of behavior or moral guidelines like 99% of heroes, it's an absolutist maxim that he forces upon others. It's the difference between being a vegetarian and breaking into people's houses and waterboarding them for daring to put honey in their morning tea because honey isn't vegan. Batman is the psychotic vegan of superheroes.

If Batman villains were slapstick lighthearted frienemies like Flash's rogues, who have an explicit in-universe agreement not to kill any civilians in exchange for Flash not brutalizing them, it would be one thing. But Batman's villains have the highest body counts of anyone who's not a cosmic planet buster like Brainiac.