Stories come from violence, they come from sex. They come from death. They come from the dark places that everyone has to go to, kind of wants to, or doesn't, but needs to deal with. If you raise a kid to think everything is sunshine and flowers, they're going to get into the real world and die. That's the reason fairy tales are so creepy, because we need to encapsulate these things, to inoculate ourselves against them, so that when we're confronted by the genuine horror that is day-to-day life we don't go insane.
"Joss Whedon: Conversations". Book by Cynthia Burkhead, March 29, 2011.