Since we were kids, we've been taught the difference between good and evil. But the world is not black and white anymore, even in the realm of movies. Here are reasons why we're so captured by those "bad guys".
Villains（反派主角） are realistic. Studies have proven that we are more likely to sympathize with characters who are similar to us. Good guys are often portrayed in movies as nearly perfect, and it's hard to relate to them. We all have our own imperfections and a dark side. So, villains are often more realistic than good guys are.
At the same time, modern antagonists aren't 100% evil. They're complex and troubled characters who have their own story. Everyone hates Dolores Umbridge from the Harry Potter movies because she's unreasonably ill-natured. There's no story and no logic behind her behavior. She's just self-serving. But many antagonists actually have their point which we see, and often even accept. We see what they're going through and what they're thinking, and we can't help but empathize with them.
We're curious about them. Every time we see a person acting bad or weird, we want to know why. And that makes us eager to know more about them, about their past, and about what they're even thinking. They're controversial, and we like to analyze these characters and their actions. They're not pure evil, and modern movies do a good job of emphasizing this. There's something that made them evil or something that won't let them be good. There's some internal conflict constantly going on within the character that we just find fascinating.
Villains are unpredictable. We never know what will happen to the villain. And that makes us care about them during the whole story. It's what gets us hooked on watching them through to the end. Also, you can't predict their actions. There are not many options aside from the right thing to do for the hero. But there're many absolutely crazy possibilities for the villain that we couldn't come up with even in our wildest dreams. And this makes us interested in watching them.
