I'm first and foremost a reader.
Sometimes I'm a blogger (who writes poorly constructive sentences).
But never an author. Unless it's a 2-20 page essay on some random topic that teachers have assigned, my "creative" writing skills stops there.
FanFiction (Unleash Your Imagination!!). Or I turn to FF when I love the characters or plot, but am not a big fan of what the original creators did with it. The MC dies in the end or the love interest goes away? Pffft. Not in FF land. In FF land anything goes...and goes and goes to places where they should not have gone.
I admit that I wrote a fanfic or two. It was horrible; I took it down like 2 days later.
I'm not discouraging anyone from writing. If you're passionate and really enjoy writing, then be my guess. Just don't expect me to fall in love with your works. I commend the people who take the effort and publicly post their works. There are just some FFs that I question if they are serious and if I should take them seriously.
I hate trollers and I hate people who just bash, but if the writers don't care, then why should I?
Some fics are TYP3D LKE DIS and the characters go like OMG WTF HRYFBFASDINA!!!!!111! LOLMAFO. Please, please for the sake of the English language, stop writing like you're texting. Even then, if I can't read it there's no point in texting/writing. They need serious editing. Just like how novels need editors to catch the small mistake or point out some better ideas, FF writers need beta readers who can proofread. Your and you're are two different words. OMG WTF AFSAIFNASKDAD!!!11!! is not English.
Some fics blatantly plagiarize other works of fictions: FFs or published novels. For example I read a Twilight FF that copied from Thirteen Reasons Why: exact storyline and from what I've heard, exact passages from the book too.
Some fics, the writers take to the extreme. There are regular pairings like for example Edward and Bella from Twilight. Then there are "crack" pairings like Jane and Seth that doesn't even make sense. And I can't tell if the writer is trying to be different and new and challenging themselves or if they just don't realize how much of their fanfic doesn't work. At that point, it's no longer a fanfiction, but your own work with the same appearance and name.
Some fics are abandoned. Suddenly and without warning. It could be a fanfic that you actually really enjoyed and looked forward to its updates. But the writers have a life outside of FF and FF doesn't pay the bills. I get sad.
So once you cleaned away from the muck, there are a couple of gems in there. They're far and few, but they make the search so worth it. Great writing that immediately pulls you in, a set of characters that you love, and a fantastic storyline that is utterly thrilling and makes the heart race. These great FF gems are better than some of the published novels I read based on character development, storyline, and ending. Then I wonder why aren't they published.
And you know what? Some do publish their works. The great feedback from the readers can give a boost of confidence for the writer to consider publishing their work: indie pub, self-pub, or seek traditional pub.
Cassandra Clare, author of the Moral Instrument series and the Infernal Devices series, did fanfiction. Of course there's some scandel there. There's also RJ Anderson, author of Faery Rebel series and Ultraviolet who still has an active FF account. There's probably some more hidden YA and FF writers out there ;)
Before starting your adventure in fanfiction, here's a nice glossary with the terminology in the FF world to help along. There's enough abbreviations to make a whole new language.