Perhaps in the fanfiction's plot, there are some dark secrets associated with Minato and Kushina. Maybe they were involved in something that Naruto, with his strong sense of justice, couldn't forgive. For instance, if they were unknowingly part of a plot that caused harm to the village or its people in the past, and Naruto discovers this, it could fuel his hatred.
In some fanfictions, it could be due to a different upbringing. If Naruto was raised in an environment where he was constantly told false things about Minato and Kushina, he might develop hatred towards them. For example, if he was led to believe they abandoned him on purpose instead of sacrificing themselves for the village.
One possible reason could be a miscommunication in the fanfiction. Maybe some secrets were kept from Naruto about his parents that made him feel betrayed when he found out, thus leading to hatred.
In some fanfics, Naruto might be made to hate Minato and Kushina due to a sense of abandonment. If the story is written in a way that emphasizes how Naruto grew up alone and suffering, he could project his anger onto his parents for not being there for him. For example, he might think that if they were alive, he wouldn't have had to endure the taunts and loneliness in the village.
At first, Naruto and Kushina might start to distance themselves from Minato. They could avoid him and not talk to him as much. As time goes on, the hatred might grow deeper. Naruto could start to oppose Minato in public or in important village matters. Kushina might also try to influence others in the village against Minato.
One reason could be that Minato values the original narrative and the way his story was intended to be told. Fanfiction can sometimes introduce elements that he might find inappropriate or not in line with the values and themes of the Naruto world. For example, some fanfictions might create overly dramatic or out - of - character scenarios for him, which he would not approve of.
It could be that in the fanfiction, there are made - up events that lead Naruto to hate Minato. For instance, if there is a plot where Minato was thought to have some dark secrets that affected Naruto's life badly, like being involved in some sort of conspiracy against Naruto without his knowledge. This would give a reason for Naruto to hate him.
Maybe it's because of the hardships Naruto endured due to Minato's actions. Minato's decision to seal the Nine - Tails in Naruto made him an outcast. In fanfiction, this could be exaggerated to the point where Naruto blames Minato for all his pain and suffering, leading to hatred.
It could be that she values the authenticity of the original Naruto story. Fanfictions often introduce all kinds of wild ideas and concepts that she might find disrespectful to the carefully crafted world of Naruto. For example, some fanfictions might change the relationships between characters in a way that goes against her understanding of the Naruto universe.
It might be due to jealousy. If Minato was getting more attention or praise in the village for his achievements while Kushina felt overlooked, that could create resentment. Say, Minato was constantly being hailed as a hero for his speed and battle tactics, and Kushina, who also had great power, felt like she was in his shadow.
Well, in fanfics, sometimes authors like to take a completely different approach to characters' relationships. In the case of Naruto hating Kushina, it could be related to a power struggle within the fanfic's plot. Maybe Kushina has some power that Naruto feels threatened by, or there are political or family reasons within the made - up world of the fanfic that cause this animosity. It's all about exploring new and unexpected ideas in the world of fanfiction.
One possible reason could be a misunderstanding. Maybe Minato thought Kushina had done something to endanger Naruto when in fact she hadn't. In the heat of the moment, he lost his temper and slapped her.
Well, in some fanfics, Minato might see more of himself in Naruto. Naruto has his determination and the will to protect the village just like Minato did. Also, Naruto being his son, he could have a special connection that he doesn't have with Kushina in the same way. Maybe Naruto's journey to become a great ninja reminds Minato of his own past, so he has a stronger liking for Naruto.