What's a story without a villain? Nothing.
We may not like the bad guy but we'd be no where without him. Writers and readers learn to love to hate the villains.
Take the story Peter and Wendy. Peter, the boy who wouldn't grow up was interesting, the relationships between Wendy & Peter and Tinker Bell & Peter make a nice triangle but without Captain Hook and the Pirates, we'd be reading a travel story.
We're sympathetic to the hero of the story but think of your favorite story, the villain moves the story along in ways that hold your attention.
So the next time you love a story, don't just thank the hero, thank the villain too.