Expanding my thoughts:
One of the most significant reasons that Under the Red Hood was so compelling was the conflict and moral stances taken by Bruce and Jason, which were even more emphasized by the story really going for Jason as a foil to Bruce (particularly drilled home by all the lines drilling home both that Jason as Bruce’s son and also that Bruce thought he’d surpassed him and the quiet fear he had that he couldn’t stop him because of it).
DC isn’t very good at exploring the moral complexities, and Winick himself was surprised by just how sympathetic and relatable Jason ended up being for a lot of readers. This coupled with the very vehicle of comics and its long-running villains, which works in opposition to half the rhetoric they push as ‘right’, undermined and continues to undermine certain aspects of that conflict. They think in the end it’s clear cut that Bruce is in the right and frame a lot of stories--not just his conflict with Jason--in this same way (he’s right because he’s Batman happens a lot, and you can see non-Batman comic fans get annoyed at it all the time).
Yes, Jason asking someone who is morally against killing for their own mental health to murder as proof of love is not a reasonable demand, but Bruce actively going out of his way to preserve the Joker’s life, when the Joker is an irredeemable murderer who has killed many and will go on to kill more because they can’t hold him permanently and know this through experience, is a tier above and beyond understandable moral quandaries straight into a special kind of moral absolutism that, imho, goes too far.
In the end, it’s comics they do half these things not even for in-story or character reasons (the no-kill rule started as a mandate from the comics code authority and it was much looser until the mid-90s where it became a huge Thing), but there’s a reason people react the way they do and it’s not as simple as ‘Batman should or shouldn’t kill the Joker’.













