Well, that's certainly summarizes JackBauer's post, at least.
In any case, I think the reason it's always made a personal struggle with heroes and villain (in most good/bad guy movies, actually) is because it works the best in a two hour time frame. Firstly, almost no one cares about a villain who's not at all connected to the hero. In any form of media. Do people read Batman or Spider-Man to see them beat up random thugs? No, they don't. They read it to watch them fight The Joker, and Doc Ock, and all of those guys. For whatever reason, people like personal struggles. That's made even more evident by the fact that all of the most famous villains, are the ones who have done the most damage to the hero's personal life (The Joker, Green Goblin, etc.).
The difference, however, between comics and film is, in comics, you have a lot more time to build relationships and characterization and, well, hatred between characters. The Joker killing Robin and crippling Batgirl - not to mention the killing of hundreds of innocents - that's all done over a rather long period of time. As are the Green Goblin's crimes against Spider-Man. In a film, when you only have 2-some hours to tell the whole story of the struggle between hero and villain, you need to cement that mutual hatred quickly and effectively. And the easiest way to do that is doing what Burton did with the Joker in B89, or what they're doing with Sandman now in SM3.