“Fan fiction is what literature might look like if it were reinvented from scratch after a nuclear apocalypse by a band of brilliant pop-culture junkies trapped in a sealed bunker. They don’t do it for money. That’s not what it’s about. The writers write it and put it up online just for the satisfaction. They’re fans, but they’re not silent, couch bound consumers of media. The culture talks to them, and they talk back to the culture in its own language.”
People ask where I started, why I started writing and I have no problems telling them it was fanfiction. Where is there a better and more safe place to find others who will be receptive to your ideas? So you don’t own the characters, so what? A per-created universe is a good environment to get started in. The original thoughts and ideas will come eventually. Hell, I still write fanfiction at least once a month and have met some absolutely incredible writers this way.
To each their own.