Maybe the kid finds the plots in school hero novels too predictable. For example, the hero always overcomes difficulties in a similar way, which makes the story boring.
Perhaps in this high school fanfiction setting, Percy has a different group of friends who don't like Annabeth. Their influence on Percy gradually makes him develop a dislike for her. You know, peer pressure can sometimes change a person's attitude towards others.
They are important because they stimulate kids' imagination. For example, stories set in a cool school can make kids think about different kinds of learning environments and adventures that could happen there.
It could also be due to jealousy. Peter might be getting too much attention from the public or other superheroes. His youth and new - found popularity could make the more established Avengers feel overshadowed, leading to feelings of resentment towards him.
Maybe humans have been over - capturing Pokémon without considering their well - being. In the fanfic, this could lead to Pokémon feeling like they are just objects to be collected. So they start to hate humans.
In the Naruto series, Sakura was often portrayed as a bit of a damsel in distress early on. Some fans who really like strong, independent female characters might not like her for that. So they write 'naruto hate sakura fanfiction' as a way to vent their frustration with her character development. They may think she didn't grow as much as she could have in terms of being a truly capable ninja on her own, without always relying on the male characters around her.
Maybe Tails hates fanfiction because it often goes against the original vision of the character. Fanfictions might portray him in ways that he doesn't like or in situations that are inconsistent with the official story.
It could be that Naruto hated fanfiction because it can sometimes create false expectations among the fans. His real story is about hard work, friendship, and perseverance. But fanfiction might focus on other aspects like shipping him with random characters in a way that doesn't fit his true nature. Also, he might see it as an intrusion into his personal story that he and his friends have worked so hard to build in the original series.