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?
It makes sense, I suppose. maybe I'm just a bit jaded about villain writing. I just feel like a lot of the time villain motivation seems to come after the villain themself. Like the villain and their methods was created, and then a motivation for that was created to make it make sense. Rather than creating a motivation and then designing the villain off the motivation. Not all villains, of course. there's some pretty complex and fantastically written ones out there. But sometimes, there's a lot of villains where it seems the writers just REALLY needed some kind of relatable motivation.