Winning the villain over to your side is a power fantasy.
Like, a really big one, too.
Social emphasis has it that men should value strength, aggression, and violence, and women should value kindness, empathy, and community. But really, anyone who has learned to prefer social success to might/aggression is going to favour a strategy where you can make your enemies into allies of some kind, over one where you just kill them. As a display of dominance, killing is overly simplistic. And it’s also hard to ignore the reality that luck usually has more to do with most fights than actual strength.
So, many people vastly prefer stories where the villains don’t die, but instead, get won over by the hero. It’s also a much more prevalent power fantasy among women than it is among men, because women are often taught that violence on our parts is inherently distasteful and ignoble. If you can’t defeat your enemies by putting a bullet in their heads, then what could be more satisfying than convincing that enemy to come and fight other people on your behalf instead?
This is a major component to why villains end up as popular shipping material. I honestly don’t think it’s the ‘bad boy’ impulse, or some branch of misogyny, or at least, not in a majority of cases. It’s a total and sincere power fantasy. Someone going ‘all I care about is myself and all I want to do is DESTROY THE WORLD MWAHAHAHA’ meeting you and then being like ‘oh no wait I also want to please you and spend time with you and I want that so much that I will now give up those other things’ implies an intoxicating level of charisma.
Of course, like most power fantasies, it pays to tread carefully with it. Because real life rarely accommodates such things, and as with some muscle-bound hero easily lifting a house over his head, being able to take a wholly selfish being and convert them into a devoted companion is… unlikely to happen outside of fiction. For a lot of reasons.
However, I bring it up because I am C O N S T A N T L Y seeing the compulsion to ship characters with villains misattributed to A) agreeing with the villains, B) some form of self-hatred, C) a noble impulse towards compassion and understanding, or D) sheer stupidity, and really… it’s just another power fantasy. Wonder Woman punches a tank. Tony Stark buys an entire island. Storm calls down a lightning strike. Batman outwits all his clever foes. And some seemingly random, ordinary human woman convinces Lex Luthor to chill out and stop trying to kill Superman. It’s all power, displayed in fantastical proportions.
(Which isn’t to say that you have to like it or think that every such relationship is good and healthy, gods no, but once you realize that everyone’s just pretending to be the Superman of relationships, it’s easier to just go ‘oh that’s what you’re after’ and… y’know… fret less.)