You seem to infer that by personal I meant that the hero should be driven by selfish motives, but I implied no such thing, just that for a villain to be interesting for 20 episodes, it can't be just the hero purely mechanically stopping the villain's evil plans week in, week out. Some connection between them has to form (or preexist) otherwise one might as well get a different villain every week.
Form, sure. The specific thing I've been talking about all along is the tendency in much series television today to have every storyline revolve entirely around the protagonists themselves, the consequences of their own actions, or their immediate family. The complaint was that the big bads this season weren't sufficiently personally connected to Supergirl, and I don't agree with that. She had an emotional stake in Cadmus due to its effect on her foster family as well as her concern for the welfare of her fellow alien refugees on Earth, and she had an emotional stake in Rhea's actions through Mon-El and as a result of Rhea's personal vendetta against her. What I'm saying is that she could
form personal involvement in a storyline without having to have a
pre-existing personal connection to the people driving it, as she did with Astra. I think you're basically saying the same.
But I, for one, don't need a hero to have some specific personal reason to care about fighting the bad guys, like a member of their family being hurt or the situation reminding them of their daddy issues or whatever. I think people caring about other people should be the default. Especially for someone like Supergirl. She cares about everyone. It shouldn't matter if it's her best friend or someone she's never met before -- she'd be just as saddened to see them hurt and just as eager to help and protect them. You can certainly get good stories out of a character's connection to a guest star, like James and the alien boy the other week -- or, heck, like most series television prior to a couple of decades ago.
And the Batman/Joker example is actually exactly what I'm talking about, that's the hero/villain relationship where the focus of most stories where they face each other, certainly the focus of the most famous stories, is precisely on the personal conflict between them, and not on the selfless saving of civilians. Of course Batman opposes Joker for selfless reasons, but the meat of the story is never in just that...
But that's just what I'm saying. It's only personal from the Joker's end, because either he resents Batman for constantly stopping him or is fixated on Batman as his favorite opponent in the "game" he thinks he's playing. Batman doesn't need a personal motive to counter the Joker, beyond the personal loss that drives him to do everything in his power to make sure that nobody else has to suffer the same pain he did. Yes, some stories have tried to make it more personal by having the Joker kill Robin or paralyze Batgirl or whatever, but that's superimposed onto a conflict that was already well-established without it -- and, indeed, part of the point of
The Killing Joke was that it didn't actually change anything from Batman's side of things. The Joker wanted it to drive Batman and Gordon over the edge, but they refused to let it, as awful as it was. They still did things by the book (insofar as the book allows for a guy in a cape and mask), and Batman still even tried to reach the Joker and reason with him, to break the cycle of violence before it got worse. The enemy that Batman has a personal vendetta against isn't the Joker -- it's
crime. All crime. He doesn't want anyone to have to suffer the way he suffered, not if he can help it. So every fight against every criminal is equally personal to him. That one horrible moment under that streetlamp (it wasn't actually an alley -- that's just a nickname the street acquired) was the most personal motivation imaginable. So any attempt to graft on a more personal vendetta against any particular villain is superfluous to Batman's character.