What's so bad about Fanfiction?

So what's so bad about being a fanfiction writer? (FYI the link is to my author page at Adult Fanfiction) I personally see nothing wrong with it.  And I'm not ashamed to say that I've ventured into writing fanfiction. I'm starting with areas I know really well. Like Sailor Moon and stories based on the World of Darkness, belonging to White wolf. But I told a few close friends and they went, "What?! Well if you have fun doing it that's cool but don't tell anyone!"

That made me start to think. What's so bad about writing fan fiction. It's not like I'm selling my fanfiction or even making money from it. I'm simply writing my own stories and such based on a world I very much enjoy. It's for my own enjoyment so what's so bad about that? Why is this something I'm supposed to be ashamed to admit?

Currently I'm only at adult fanfiction because I plan to deal with topics that may or may not be acceptable. I've some horrors I need to work out and I've found that writing them out with characters and seeing how the characters overcome them are helping me overcome them. Kinda weird no? Well anyways, what are your thoughts? Is anyone reading this? I know it's new but was curious if anyone had found me. Anyway, that's it for now. Thanks for reading... and here, for your pleasure, is a picture of one of my favorite new artists i've found. She's from Deviant art. Check out her gallery she's amazing!