She might hate sonic fanfic because she has her own ideas about how Sonic's story should progress. Fanfics are written by many different people with different interpretations, and perhaps she doesn't agree with the general direction that a lot of fanfics take. Also, some fanfics could be poorly written, which might also contribute to her dislike.
Well, she could simply avoid reading them. There are plenty of other things related to Sonic that she can engage with, like the official games, comics, or animated shows.
Maybe she feels that fanfic often distorts the real relationship between her and Sonic. In fanfic, their characters might be misrepresented, which could make her uncomfortable.
Maybe because she sees the love and effort fans put into it. Sonic fanfic is a way for fans to express their creativity and love for the Sonic universe, so Amy might want to defend that.
It could mean that Amy (presumably a character from the Sonic universe) is standing up for Sonic fan - created fiction. Maybe there are some who are criticizing Sonic fanfic, and Amy is in support of it, perhaps because she values the creativity and passion of the fans who write such stories.
Often, she will be very protective. Amy would try to shield Sonic from any further harm. She could stand guard over him and not let anyone or anything get close that might pose a threat.
In some fanfics, the idea of Naruto hating Hinata might be a plot device to create drama. Maybe the writer wants to explore a different kind of relationship dynamic than the canon one. It could also be that the writer has a unique interpretation of the characters' personalities and how they might clash in certain situations.
Maybe in the fanfic, the writer wants to create a unique plot where Aang has some misunderstandings about Katara. For example, he might misinterpret her actions or words, leading to dislike.
Maybe the writer wants to create a unique plot twist. In some fanfics, authors like to deviate from the original relationship to explore different character dynamics.
Maybe the OC has a completely different personality or set of values from what is often portrayed in Rias fanfic. It could be that the OC has had bad experiences related to the typical tropes or themes in those fanfics.
Maybe it's because Aphrodite's powers and the way she uses them are at odds with Naruto's own beliefs. Naruto believes in self - improvement through training and facing challenges head - on. If Aphrodite uses her love - related powers in a way that seems unfair or goes against Naruto's sense of justice in the fanfic, he would dislike her. Like if she uses her powers to manipulate people's emotions for her own gain, which is something Naruto would oppose.