In my experience fan fiction is usually written by people who suffer from some sort of immature infatuation for a character in a game, film or whatever and fantasize about what that character would be like in situations not portrayed in the original material. A lot of times, that infatuation is accompanied by some sort of romantic feelings for said fictional character. As such fan fiction tends to devolve into silly, superficial writing without any aim except to slake the feelings of the writer towards the characters who are the object of their attention.
Forgive me if I'm being elitist in pretentious.
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