Well, sometimes in fanfiction, the author might want to explore a darker side of the relationship. Ginny could cheat on Harry because she realizes that she got into the relationship too quickly. Maybe she thought she was in love but later found out she wasn't as into Harry as she thought. Or perhaps there is a new character introduced who has a certain charm or power that Ginny finds irresistible, and she succumbs to the temptation, which leads to her cheating on Harry.
In fanfiction, Ginny could cheat on Harry due to a sense of adventure. She grew up in a large family and was always a bit of a rebel. So, she might be tempted to have an affair with someone who represents a more dangerous or exciting lifestyle. Also, it could be that she has some unresolved issues from her past, like her experience with Tom Riddle's diary. These unresolved traumas could make her act out in ways that include cheating on Harry.
One possible reason could be jealousy. Maybe Ginny feels overshadowed by Harry's fame even within their relationship and she strays to someone who makes her feel more special on a personal level. Another reason could be miscommunication. If they have been too busy with their respective wizarding duties and haven't been communicating well, Ginny might feel neglected and be drawn to someone else who seems to give her more attention.
It could be due to jealousy. Perhaps Ginny has been spending a lot of time with another character, and Harry misinterprets their relationship, leading to his anger. In fanfiction, the writers often play with such emotions to create drama.
One possible reason could be miscommunication. Maybe Ginny feels neglected by Harry because he's so caught up in his own heroic deeds and doesn't pay enough attention to her. So she might seek comfort or excitement elsewhere.
She might hate it because it could change the way people see her character. In the original story, she is a strong and independent person, but fanfiction might portray her in a wrong way.
In the fanfiction world, it could be a prophecy. There might be a prophecy that says Harry's presence in Ginny's life will bring great harm to her or the wizarding world. So, for the greater good, Harry leaves. He believes that by sacrificing his relationship with Ginny, he can save her and everyone else. It's a very noble but also a very heart - breaking decision.
Maybe in fanfiction, Ginny discovers that Harry still has some unresolved feelings for Hermione. This could create a rift between them and lead to a divorce. It's not uncommon in fan - created stories to explore complex love triangles that were not fully resolved in the original series.
Another reason might be some kind of external influence, like a powerful dark magic that clouds Harry's judgment. However, this is often a stretch from the original concept of the characters. Fanfiction writers sometimes like to explore extreme scenarios to add drama to the story.
One possible reason could be jealousy. Maybe Ginny gets jealous of Harry's friendship with Hermione. Another reason might be differences in their future plans. For example, Harry may want to focus on his Auror career more than Ginny anticipates, causing a rift between them.
One possible reason could be a growing apart due to their different career paths. Harry, being deeply involved in the wizarding world's security and Ginny having her own Quidditch career. Another reason might be the stress of living in the public eye. Their relationship may not be able to withstand the constant scrutiny and pressure from the wizarding community.
In some fanfictions, Ginny may reject Harry because she wants to focus on her own personal growth. She might feel that a relationship with Harry at that time would hold her back from achieving her own goals, like becoming a great Quidditch player or an accomplished witch in her own right. So, she decides to reject him to pursue her own dreams first.
One possible reason could be a creative twist by the author to explore different relationship dynamics. Maybe they want to create conflict and drama. For example, the author might make Harry misunderstand Ginny's actions or intentions, leading to this false sense of hatred in the fan - made story.