To switch metaphors, I think that one reason there are some very enjoyable fanfics (even if the writer doesn't have a lot of formal education or standard literary technique) is that the writer really believes in the story and has visualized it in detail. (And that's one reason why fans can read a number of superficially very similar stories and continue to enjoy them--of course, other things are at play too.)

Whereas if the writer essentially doesn't really believe in the story, it can be all blahblah blow stuff up blahblah jail cell blahblah alien sex pollen blahblah buttsecks blah blah soulbond.