I would say that maybe directors who act as well are easier with actors. I'm not saying that all directors have this, but sometimes you'll come across a director who sort of looks at an actor a bit like a kind of untrained horse that's been let out of the stable, like they might buck him.
People are fascinated by evil because it's mysterious and it doesn't seem to have a rationale behind it, and the second you say that Hannibal Lector was abducted as a child and he had to eat his sister or something like that, it becomes immediately mundane. The character becomes mundane.