I do know that fanfiction's probably as old as mythology itself--retelling is what we humans DO.

I think "complicated and less happy" = "more interesting." But me, I find that if you make it TOO bleak, it's as ridiculous as if you make it too saccharine. I like a happy medium.

Also, we may like to take the idea and see what WE can do with it. Just because one person did one thing with a premise doesn't mean there aren't other possibilities!