This article really makes sense.
I think back on my past and all the evil actions I have taken have all been fed by very low self-worth and insecurity.
When you think of yourself as below everyone else, trying to bring them down to your level with malicious acts can feel like quite reasonable. You're "punching up" so you can feel a sense of righteous justification.
It's only looking back that I realize I wasn't nearly as weak as I thought.