I got my start writing fanfiction, then inched out into original works after that. I tried my hand at fanfiction again a few years ago and Christ, it was much more difficult than I remember it being. Kudos to those who do it.
I write mostly for myself. If I write something and it gets a favorable response, then I keep that in mind, but mostly I write what I like. If I wrote something just to feed the audience, and it wasn't something I was at all interested in, 1) it would suck and I wouldn't have fun, and 2) I think my lack of enthusiasm would show in the finished work. Neither of those alternatives are acceptable to me.