Naruto is a character with a strong sense of identity. He is a ninja from the Hidden Leaf Village. The idea of being put into a Wonder Woman fanfiction might be seen as diluting that identity. He has his own goals and missions within his own universe, and being thrust into a different fictional setting like that of Wonder Woman could be seen as inappropriate from his perspective. So, this could lead to the perception that he hates such fanfiction.
It might also be related to the fan bases. Naruto has its own dedicated fan base, and Wonder Woman has hers. When fanfiction tries to merge the two, it might not sit well with either group. The Naruto fans might not like their beloved character being used in a way that they feel is not in line with his original story, and the same could be true for Wonder Woman fans. This could contribute to the idea that Naruto hates Wonder Woman fanfiction.
Jiraiya was a serious shinobi with a certain code. Fanfiction might play around with that code too much for his liking. It could make light of things he held in high regard, like his loyalty to the Leaf Village or his training of Naruto. So that's a possible reason for his hatred.
One possible reason could be a misunderstanding. Maybe some false information was spread about Kushina that made Naruto believe she was a bad person. For example, if there were rumors that she abandoned him for some untrue reason, it might lead to his hatred.
It could be that Yugao has a connection to an enemy or a group that Naruto dislikes. This connection could make Naruto view her with suspicion and ultimately hatred. In some fanfiction scenarios, she could be unknowingly involved with a plot against Naruto or his village.
One possible reason could be feeling betrayed by the village's secrets and politics. Maybe he discovers some dark underbelly of the Leaf Village that makes him lose faith in it.
It could also be related to personal relationships. Tsunade might have been hard on Naruto in a way that he felt was unjust. Perhaps she was overly critical of his unorthodox ninja techniques or his impulsive nature, and over time, this built up into hatred. Naruto, being someone who values respect and recognition, could have resented her for not seeing his potential in the way he wanted.
One possible reason could be the pressure associated with the Hokage title. Naruto has always been in the spotlight and being Hokage comes with a huge burden of responsibility. Maybe in the fanfiction, he resents how it restricts his freedom to just be himself and have adventures like he used to.
There are several potential reasons. Catwoman's agility and stealth skills might be a source of envy for Wonder Woman. While Wonder Woman is strong and powerful, Catwoman's ability to slink around unseen and steal things right from under people's noses is quite impressive. In addition, Catwoman's relationships with other characters, especially those in Gotham, might be more complex and nuanced than Wonder Woman's relationships in her own world. This complexity could lead Wonder Woman to feel jealous in fanfiction, as she may long for more interesting and less straightforward relationships herself.
His connection with Gotham City. Batman has a deep and personal connection with Gotham, and the city almost seems to be an extension of him. In fanfiction, Wonder Woman, who is more associated with Themyscira, might envy this strong bond. She may feel that his relationship with Gotham gives him a unique identity that she lacks in relation to any particular place.
One reason could be that it doesn't respect the original story's intention. The original Naruto story is about growth, friendship, and ninja skills. Harem fanfiction for Team 7 just throws in romantic elements that Naruto may find disrespectful to the real story.
One possible reason could be that he feels burdened by the expectations associated with the Uzumaki clan. Maybe he doesn't like the constant attention or the pressure to live up to the clan's legacy.