One reason could be for the sake of the Naruhina relationship. To make Hinata seem like a better match for Naruto, the writer might make Naruto hate Sakura. For example, if Sakura is written as being too pushy or bossy in the fanfiction, Naruto could start to dislike her.
There are multiple reasons in Naruhina fanfiction for Naruto to hate Sakura. It could be related to Sakura's own actions towards Naruto. Maybe she rejects Naruto in a really cruel way in the fanfic, which makes him turn his feelings into hatred. Or perhaps the fanfic writer wants to explore a different emotional path for Naruto, and having him hate Sakura is a way to do that. This can add more conflict and depth to the story as it shows a different side of Naruto's character compared to the original series.
Well, in Naruhina fanfiction, the idea of Naruto hating Sakura can be a device used by writers. It could be due to jealousy in the context of the story, like if Sakura is shown as being too close to someone Naruto doesn't like. Or it could be a misinterpretation on Naruto's part of Sakura's actions. But this is all part of the fictional world of fanfiction, and not a given in the overall Naruto universe.
It could be that in the fanfiction, Naruto's character is developed in a way that Sakura, within the sasunaru concept, doesn't approve. For instance, if the fanfiction makes Naruto too weak or too different from his original self. Also, if the fanfiction focuses too much on certain relationships that she doesn't like, she would hate it.
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.
One possible reason could be for the sake of creating a more complex love triangle in fanfiction. Maybe the writer wants to explore a different dynamic where Naruto and Hinata's relationship is strengthened by having a common dislike for Sakura. It could also be that the fanfiction writer is trying to give Hinata more agency and make her a stronger character by having her oppose Sakura in some way, perhaps in matters related to Naruto's affections.
In fanfiction, Naruto could hate Sakura due to her treatment of him. She often overlooked his feelings in the original series. Fanfic authors might exaggerate this aspect. For example, if Sakura continuously dismisses Naruto's achievements or makes him feel inferior, it can build up to a strong dislike or hatred in the fan - created stories. Also, some fanfictions might explore a darker side of Naruto where his pent - up emotions turn into hatred for Sakura, perhaps as a way to show his growth into a more complex character with a wider range of emotions than just the positive ones shown in the original anime.
Another reason could be that she values the authenticity of the original Naruto narrative. Fanfictions are often the product of fans' wild imaginations and might not align with the official story. She might be a purist when it comes to the Naruto story she is a part of, and thus hates fanfiction that strays too far from the original.
One possible reason could be that in some fanfiction, Naruto might be written to hate them because of their early treatment of him. Sakura was often dismissive of Naruto in the beginning, and Ino was more focused on Sasuke too. So in a different narrative, Naruto could hold grudges against them for not seeing his worth initially.
Well, in fanfic, the writer can take creative liberties. It could be that Naruto has grown and evolved in a different way than in the original story. He might have seen Sakura's flaws more clearly over time. For example, her obsession with Sasuke could be seen as a negative trait that affects the team dynamic. And as Naruto values the team highly, this could cause him to develop a dislike and eventually hate for Sakura.
In fanfiction, if a Naruto character were to hate Hera, it could be due to a power struggle. Maybe Hera tries to impose her rules on the Naruto universe which is used to its own way of things. For example, she might try to regulate the use of chakra as if it was some form of divine energy she could control.
In NaruHina fanfictions, Naruto might ignore Sasuke because he finally finds true love and stability with Hinata. His focus shifts from the turbulent relationship with Sasuke to building a future with Hinata.