10 Problems With Batman Nobody Wants To Admit
10. The No Killing Rule
Obviously that's not really the first part, but Batman's ongoing relationship with The Joker is a part of the character that deserves more discussion than it does currently. The idea of Batman not killing does come up fairly regularly in fanboy discussions, but neither side ever tends to give the other much leeway: either you're an idiot for siding with Batman, who infamously refrains from killing his enemies (especially with guns) because that would make him as bad as the criminals he's trying to lock away - like the one who murdered his parents, for example; or else you're a bloodthirsty maniac who wishes that relatively innocent superhero comics should be as full of consequence-free killing as your average action blockbuster.
Neither is totally correct, but the bloodthirsty lot might have more of a point. Applying real-world ethics and logic to a superhero comic is a bit silly, but hey, you're the one reading a list of problems with Batman. No judgement here.
So with The Joker as an example - although really this could apply to any member of his rogues gallery - what is gained from keeping Joker around? The moral high ground for Batman, sure, but he must know every time he catches him and tosses him in Arkham it's only a matter of time before the clown prince of crime breaks out. And when he does, he'll murder a bunch more people.
Why not stop him more permanently if not murdering him himself, then by enforcing the death penalty?