Just to make sure we're on the same page ... I wasn't trying to suggest that fanfics are better than Hollywood's films. I was pointing out that fanfics, 99.9% of which are abysmally awful, tell us that fandom does not make somebody qualified to write, act in, or otherwise produce a film adaptation of a book, video game, comic, etc. Being a fan begins and ends with itself: being a fan. If I'm a fan of Go, it doesn't make me skilled at it. If I'm a fan of Beethoven, it doesn't mean I can perform his pieces, much less compose some of my own which rival his. If I'm a fan of Cowboy Bebop, it doesn't mean I can write a script for a 2nd Bebop OAV so well that I'd have the fans busting down my door just to get my autograph.
Your reply left it unclear to me if you understood that. Maybe you did? Probably you did. But just in case ...
I'm not a fan of fanfics, and would be just as unenthusiastic about learning that some fanfic writer's Cowboy Bebop fic was being turned into a movie as I am about learning that Keanu Reeves is a self-professed huge Bebop fan.
Reeves may 100% not be lying and be a huge Bebop fan, but he's still a terrible pick for Spike Spiegel.
Let me put it to you another way: say James Earl Jones was verifiably the world's #1 fan of Cowboy Bebop. Would it make sense to cast him as Edward? An elderly, deep-voiced black man playing a spunky, limber, androgynous child? It wouldn't work, no matter how big a fan good ol' James Earl Jones might be.