McGhostbuster
Who ya gonna call?
Your allowed to sympathise with somebody that's been through something traumatic that messes with there mental state, even if they go on to do something truly horrific
If we went with your idea we'd never learn anything, perhaps if people see somebody going through abuse, bullying and what being ostracized does to a person and their mental state they will be a bit more empathetic in the future
I agree with your first point, but I felt the movie almost pushed the sympathy and the cheering for him to seek revenge. It should have stopped after the trauma, which would have been extremely difficult.