For hypothetical example; Father/son duo are criminals, harming, killing, and stealing innocent civilians. Superhero fights them, resulting in the father dying. Son is now portrayed as a sympathetic villain because all he wants is to avenge his father… despite all the fathers of children they murdered whilst comitting crimes.
Side question; do you feel sympathy for the villains portrayed like this?
Villains must be tricky. It’s hard to make evil motivations relatable to most people. (who I’m assuming are good people)
We really want to believe that some horrific event caused the downfall of this person, but sometimes “I just wanted to see if I could” is a legitimate, although unsatisfying, evil reason to do something.