I'm not debating morality here. I'm talking about characterization and the intelligence of the writing. Three-dimensional villains, characters who have comprehensible motivations and internal contradictions, are more interesting to read about than one-dimensional villains whose writers see them as simply "evil" and thus make no effort to understand or relate to. When I write villains, I try to get into their heads, to figure out how their choices and beliefs make sense to them and why they think what they're doing is right, even if their morality is totally twisted from my perspective. Seeing a character as "evil for evil's sake" seems distancing to me, like the speaker is looking at them from the outside and is uninterested in delving into such character complexities. I hope
that's not what the writer meant by that line, but it's not an encouraging statement.