Maybe it's just me, but I never saw Arthur Fleck as an especially sympathetic character beyond the first ten minutes or so. I was initially inclined to sympathise with him, no doubt, due to his poverty and the fact that he was caring for his ill mother, but as the film went on and the layers started to peel back, I thought he seemed to display an inherently sadistic and maliciously inclined personality.
Also, getting back to Shauner's point about the film being a false narrative: another aspect of the movie that makes me buy into the theory that the whole film is a rewriting of history being spun by the Joker, is the fact that Arthur always seems to be painted as a doe-eyed innocent who's being oppressed on a near-cosmic level, almost to the point of it appearing comical and nonsensical.
Everyone seems to act against him, just because. Randall gives him a gun and later tells the boss that Arthur tried to buy one off of him. Why? The boss presumes that Arthur stole a shoddily constructed sign and is lying about the fact that some hoodlums jumped him for it. Why? None of it makes any real sense. Everyone is characterised as being an inexplicably terrible person, to the point that it feels farcical.
And none of the blame is ever placed at the feet of Arthur. It's always someone else that has to shoulder the blame for his misdeeds, whether it be his mother, Thomas Wayne, Murray Franklin or the whole of society itself. It totally sounds like a sympathy story being spun by Ted Bundy. He also could never seem to take responsibility for his murders. That's how I read the film at least.
