There are some really amazing stories out there, stories that have been left unfinished.
And it's understandable! People get busy, people move on, people forget, people simply lose motivation, people want to do other things. It's not something to be ashamed of, nor is it something you should be berated for.
Which makes me sad to see when other users comment on unfinished works to simply say "YOU MUST UPDATE THIS!"
I understand that the reader is engaged with the story and wants MORE, I really do. To see how the stories end, what becomes of the characters... we all want to feel that satisfaction. But yelling at the authors will NOT help.
I understand that they're trying to be encouraging, but saying stuff like "I'm so disappointed that you didn't finish this book" or "I've been waiting so long for this just for you to abandon it," does not help.
In fact, it's borderline guilt tripping.
Too many times, I've seen authors look upon their own works and feel disappointed, but they're pushing out chapters just for the sake of it. No one should have to feel forced to do something, especially something they start to do for the sake of enjoyment.
So, to the readers, don't pressure authors into doing something they don't want to do, or are uncomfortable doing, try putting yourself in their shoes!
And to the authors, don't let anyone tell you what to write, how to write it and when to write it! For some people, creativity cannot be forced, and THAT'S FINE! Let it come naturally, even if it takes weeks, months, even years! As long as you are satisfied with what you've created and proud, that's all that matters. After all, think about why you started writing in the first place. Just like, art, it's for ourselves, so let it be for ourselves.
After all, when writing fanfiction, it is FANfiction; for the fans, by the fans :)
