Why is the Joker so beloved? It's a question worth pondering, primarily because the character's worship seems baffling on paper. Sure, it makes sense why he's popular; he's one of the all-time great villains, and a hero like Batman is only as good as their villain. Yet the Joker's status as an icon has grown beyond his function as a foil to the Dark Knight. The hysteria surrounding the late Heath Ledger's portrayal of the character in "The Dark Knight" was totally explicable given Ledger's James Dean-esque tragic mystique, yet Joker mania has only increased since that film. The character is on the same level as other fictional villains like Walter White, Michael Corleone, and Freddy Krueger. In terms of morality, none of these characters should be revered, yet they are.

There is an easy answer to this question, of course: such despicable villains have always drawn the...