Evil and bad people usually have actual reasons for why they are doing bad things. They aren’t doing bad things just to do them — there is usually something bad that happened in their past, etc
Just because you had a shitty life doesn't mean you can make other people's lives miserable.
I was bullied during most of my childhood and highschool years. Are you telling me that I should sympathise with my bullies because they had a rough time? I had an awful time thanks to them and I didn't go making other people's lives shitty. And I didn't have their sympathy either.
For my bullies I don't have sympathy. I don't have hate either, because they don't deserve anything from me.