The discussion of villain motives left out one of the basics: power. Or rather, of course, POWER!, possibly with some bwah-hah-hahs attached. Which is often treated as one of the silly, irrational, possibly insane options, but I think that’s missing the point a bit. Especially with some of the people we see getting power in the real world, where their motivations look suspiciously villain-like.
Firstly, power implies security. “If I rule them, they can’t hurt me”. Which doesn’t always work, of course, especially if you give more people motives to hurt you, or you break a lot of laws in pursuit of power - but still, I can fully believe that a basically-sane person with a sense of insecurity (perhaps down to a bad childhood or something, if you insist on in-depth explanations) would pursue power for that reason, and rationalise a lot of fairly horrible things along the way as “the only way I can make myself [and perhaps my family] safe from the cold hard world”.
And secondly, well, there’s the basic monkey-brain thing. The troupe alpha gets first choice of the nice fruit and the mating options. I’m pretty sure that a lot of impulses towards acquiring power (and wealth, which buys that sort of alpha appearance) come from that deep, and get rationalised on the way up towards action. It’s not terribly smart - one can these days get good food and a sex life without obsessively pursuing power - but monkey-brain stuff rarely is.
From the same topic, regarding the idea of a “Detect Evil” power… One place where the last season of Jessica Jones got a little odd (spoilers follow, obviously) was the introduction of a character who appeared to have a “Detect Criminal” ability. (With the twist that it gave him screaming headaches, so you got a rather amoral character who was driven towards virtue because the alternative felt like he was getting an icepick between the eyes, but if he could live with that occasionally he had a great blackmail business going.) Insofar as this was rationalised, the idea seemed to be that he actually detected psychopathic tendencies, which sort of works insofar as they may have a physical basis and are detectable by mundane psychological testing, but having him tell another cast member when she was slipping from hero to anti-hero status because she was making his head hurt then became a slightly iffy plot point.