>>719899420 (OP)
Most writers dont understand Batman is an insane violent psychopath pretending to be a sane vigilante pretending to be a dumb billionaire. Killing would push him off a slippery slope he's barely trying to not fall into.
They need to show that if Batman kills one guy, even the Joker, he'd just be and even more insane and dangerous Punisher.
They need to show more of Batman's real psyche, that if he crossed that line, Gotham, if not the whole world, will be filled with hanged skinned "criminals".
He needs to be absolutely brutal, but not lethal, to the people he beats up. I'm talking criplling, maiming attacks, complete ptsd inducing terror, and just complete non lethal brutality.
Keep him civil, brooding, charming etc. Just have him be a complete, but nonlethal, monster once he fights.
To really show how unhinged he is, and how bad it would be if he crosses that line.