it was only Gail who wanted to keep TKJ and only for the wrong reasons
DC wanted a full retcon just cause they wanted Barb as Batgirl
on contrast to taking away Jim being tortured (or even being in the room) and Joker's real origin and motivation(it wasnt vengeance) like how it was retconed(destroyed) hereThe character of Barbara is not the focus of the story, but I'd argue she is the focal point of the whole thing. Take her completely out of TKJ, and what are you left with? Torturing Jim with pictures of a random girl isn't going to have as much impact.
even without Barb it would had been a better version