It could be due to a prophecy or a foreseen future related to his mother that Naruto believes will bring great harm. He might think that his mother's existence or actions are leading to a disastrous path, so he hates her. Also, if there were some secrets about his mother that were revealed in a negative way, like her having some connection to a dark force in the past, Naruto could turn against her.
One possible reason could be a misinformation or false memories planted in Naruto's mind. Maybe some enemy with mind - control abilities made Naruto believe that his mother had done something unforgivable. Another reason might be a misunderstanding about her actions in the past. For example, if Naruto thought his mother sacrificed something important for a reason he didn't understand at first, he could misinterpret it as a wrong choice and develop hatred.
One possible reason could be misinformation. Maybe in the fanfiction, Naruto was told false stories about his mother that made him dislike her. For example, if he was told she abandoned him for some untrue reason.
One possible reason could be a misunderstanding. Maybe his team made a decision without consulting him, which made him feel left out and thus led to hatred. For example, if they took on a mission without him, Naruto, who values being part of the team, might feel betrayed.
One possible reason could be a misunderstanding. Maybe some false information was spread about Kushina that made Naruto believe she had wronged him in some way. And for his sister, perhaps there was some sort of jealousy or miscommunication. For example, if his sister got more attention from their father or something similar.
It could also be that Naruto has been influenced by some external force in the fanfiction. For instance, an enemy might have planted false memories or ideas in his head, making him believe that his parents and sister are bad. This false perception could then fuel his hatred.
One possible reason could be a misunderstanding within the family. Maybe there were secrets kept from him that made him feel betrayed. As for Konoha, perhaps he felt ostracized or not fully accepted by the village despite his efforts, which led to his hatred.
Perhaps they have wronged Naruto in some way in the fanfiction. They could have betrayed him, like telling his secrets to others or getting him into trouble on purpose. This would lead to Naruto developing hatred towards them.
One possible reason could be jealousy. Maybe his brother has some special abilities or gets more attention that Naruto feels he should have. For example, if his brother is really good at a certain jutsu and is always praised for it while Naruto struggles, that could lead to resentment.
One possible reason could be that Naruto feels abandoned. His father was not around during his childhood, and he had to face a lot of hardships alone. Growing up without a father figure, he might have developed resentment.
One possible reason could be a misunderstanding. Maybe some false information was spread about his mother, making Naruto believe she had abandoned him. Another reason could be related to the secrecy around his mother. If he grew up feeling alone and not knowing about her, he might develop resentment.
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.