Believe it or not, there are some things that humans just do because they're not complete blank slates. It's like avoiding pain, or having a natural inclination to love parents and family.
The only way your point is true if include genetics as a "material condition" but that doesn't conflict with what I said.
Reviewing the Joker II movie:
I didn't think it was horrible. I thought the musical aspect could have been removed entirely and it would have gone up a point. It's ultimately true to the spirit of the first movie. If the first movie made Arthur too sympathetic, this movie over corrected that a bit. Arthur is ultimately someone who was failed more than he failed himself. Him more or less saying it's all his fault at the end just seems weird considering how the inciting incident was mostly forced upon him.
Don't get me wrong, he's still a villain at the end of the day, but a tragic one nonetheless. He was thrown into an unwinnable situation, identified with the evil person they painted him as, and used that to justify his crimes.