It's not that people like sad movies that make us feel like, "Oh, my god, what a bummer." We like emotionally moving experiences, where you feel like a slightly different person and you see the world a little different, after you finish. It lets you see your own life, in a different way, and it actually makes you feel really good. And even though there might be sad content making this happen, the feeling that you're left with is one that is quite good, quite hopeful, clarifying and uplifting.