That's all very well as an abstract moral principle, Avril, a coffee-table theoretical construct, but there's no denying the sheer gratuitous pleasure to be derived from seeing members of the ruling class in pain and torment.
Evil gives you far more strings to pull. But I must say that I have never been interested in the psychology of evil, not in the slightest. Perhaps I'm not interested in evil, but in the dark sides of human beings.