There's a lot of hate out there for fanfiction. I know why but I don't think it's always justified.
When I started, it was because I couldn't get certain things, such as bands, movies, out of my head, and a writer will always have plots, characters, inside their heads, screaming at them to be written about. For me, in the beginning, they were characters and plots that already existed to a certain extent. And that was fine. It meant that I already had a starting point, and I knew there were people out there who would at least give reading it a shot. And the format, which is usually post a chapter, get reviews, write another one, get some more reviews is comfortable. You get immediate feedback, which in my experience was usually good. It was also a good confidence boost when strangers tell you that they like what you write. I'm essentially a praise whore. I did ask for some constructive criticism, but didn't often get any. I think this was more to do with the fact that no-one could be bothered to tell me when what I'd written was crap, rather than because my writing didn't need any improvement.
Sure I know that there are a lot of people who just write/read fanfiction to let quench some of their sexual frustration. There is a LOT of NSFW stuff out there. And there is quite a lot of slash fiction too. There's nothing wrong with writing about a same sex relationship. But they take it too far when they pair brothers, even fictional brothers, together. FOR THE LOVE OF GOD LEAVE SAM AND DEAN ALONE!
Google 'slash' if you don't know what it means but be warned. Out there, there be monsters.
However, fanfiction has been kind to me. It's allowed me to grow. Or so I hope. And it has shown me that there are people who will read what I write, even if they can be counted on the fingers of a pair of hands.
But it's the big bad world for me now. I don't think I'll ever put a years worth of my (spare) time into a novel length fan fiction again. The only return is a small confidence pick me up, and I think it's time that I grew up and started taking things seriously. I do want to be a writer, and I know that it may not be what my path in life is, but the only way to figure out is to try, and really try.
So, fare thee well fan fiction. It's been real fun, but it's time we parted company.