She might also dislike the fact that fanfic is often created without her input. Since it's about her and Sonic, she may feel that she should have some say in how their relationship is depicted. But in fanfic, anyone can write whatever they want, and she has no control over it, which could lead to her hatred for Sonic fanfic.
Another possibility is that she is protective of her relationship with Sonic. Fanfic might introduce elements that she feels are inappropriate or could potentially damage the 'purity' of what she has with Sonic. It's like she wants to safeguard the special bond they share in the official narrative from being sullied by unapproved fan - created stories.
It could be a way to break away from the traditional narrative. Fanfics often experiment with different scenarios. By having Amy Rose die, the writer can take the story in a completely new direction, one that might not be possible in the original canon.
In some fanfics, there could be a misunderstanding. Suppose Kushina did something that Naruto misinterpreted as harmful to him or his friends. This misinterpretation could lead to his hatred. For example, if Kushina was involved in a mission that Naruto thought put the village at risk, but in reality, she had no choice.
One reason could be jealousy. Maybe in the fanfic, Annabeth gets more attention or praise for her skills and Percy feels left out or overshadowed, which turns into hatred. Another possibility is that there's a rift caused by their different approaches to solving problems. If Annabeth's logical thinking clashes too much with Percy's more instinctive ways, it could lead to resentment.
One possible reason is that their personalities clash. Percy is often portrayed as a more outgoing and confident character, while Nico is more introverted and brooding. In a fanfic, this could lead to misunderstandings and animosity between them. For instance, Percy's bold actions might seem reckless to Nico, causing him to dislike Percy.
One reason could be that the fanfic changes the essence of their relationship. In the original, they have a certain dynamic that she values, and fanfics might mess it up.
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.
Love is a common theme. Since Amy has a crush on Sonic, many fanfics explore their relationship, whether it's her trying to win him over or them finally getting together.
One common theme is the struggle between good and evil. Sonic Exe represents pure evil, and Amy Rose often stands as a symbol of good, trying to fight against it. Another theme is love. Amy's love for Sonic drives her actions in many of these fanfics, even when facing the terrifying Sonic Exe. And there's also the theme of survival. The characters are in a very dangerous situation with Sonic Exe around, so they have to find ways to survive.
For Amy, she could become more understanding of the 'evil' or opposing side. Instead of just seeing Metal Sonic as a bad guy, she might learn to look deeper into his existence as a creation. This could make her more empathetic in general.
One reason could be a personal betrayal. Maybe a close friend from Gryffindor betrays Harry, and this makes him start to dislike the whole house. It's like when one bad apple spoils the bunch in his eyes.