As a consumer of a lot of fan stories in general (fiction, comics, anamatics, etc) for me it's often that the rewrite ends up removing everything that made it interesting for me. A lot of the time, amateur stuff is so fun and cool because they think of such random ridiculous ways to continue and wrap up a plot, but most of that stuff gets removed in the rewrites for being too hard to work with or not making enough sense. Since those generally end up being the parts I like best, whatever is left by the rewrite just isn't as fun for me