It could be that Naruto is influenced by an outside power that has a vendetta against his family. This power could corrupt Naruto's mind and make him think that taking revenge on his family is the right thing to do. For example, an ancient evil entity might target Naruto because of his family's connection to a certain power or prophecy. The entity could plant seeds of hatred in Naruto's heart by showing him distorted visions of his family's actions. But ultimately, Naruto would have to break free from this influence if he is to return to his true self.
In some fanfiction, Naruto might seek revenge on his family if he finds out they have a dark secret that goes against his values. For instance, if he discovers that his family was involved in some unethical or cruel actions in the past. However, this would be a huge departure from the Naruto we know in the original series, as he is usually very forgiving. But in the realm of fanfiction, anything can be explored. Also, it could be a situation where Naruto believes his family has been hiding their true identities from him, and these identities are associated with something he despises.
In the fanfiction, Naruto might think his family abandoned him on purpose. So, he starts to seek revenge. He could train hard to become extremely powerful. Along the way, he meets some people who try to convince him that revenge is not the answer. But his anger is so strong that he doesn't listen at first. Eventually, he might come across some evidence that shows his family had no choice but to leave him, which makes him question his revenge mission.
Another reason might be that Naruto has been influenced by external forces. Maybe he has made some bad friends or been involved in some situations that made him think being cold to his family was the right thing. He could have been brainwashed into believing that his family was holding him back from achieving something greater.
It would create a huge shockwave. Naruto is a central figure, and his actions towards his family would change the dynamics of all his relationships. His friends would be deeply divided. Some might try to stop him, believing there must be a misunderstanding, while others might be swayed by Naruto's determination. The ninja villages would also be affected. Konoha, in particular, would face an internal crisis as Naruto is one of its most important assets. His revenge could lead to a split in the village, with some supporting Naruto and others standing by his family.
It could be some hidden members of Naruto's family itself. Maybe there are relatives who have been manipulating things from the shadows and their actions led Naruto to believe he needs to take revenge on the family as a whole.
One possible reason could be that he has some unresolved issues from his past, like the absence of his parents during his childhood which made him feel a sense of detachment. Maybe he is so focused on achieving his ninja goals that he unconsciously starts to ignore his family. Another reason might be some sort of miscommunication within the family. For example, if there are secrets that the family has been keeping from him, he might feel betrayed and thus choose to ignore them.
One possible reason could be a long - held misunderstanding. Maybe Naruto discovers some family secrets that he misinterprets as betrayal or neglect. For example, if he finds out that his family had made some sort of pact that he disagrees with, it could lead to his rejection.
In a fanfic, Naruto could be driven to get revenge on his friends if there was a prophecy or some sort of fated event that made him believe they were going to be his downfall. Also, if his friends made a deal with an evil force to gain power at the expense of Naruto or his loved ones, he might feel the need to take revenge. Another factor could be extreme jealousy. If Naruto's friends suddenly got all the attention and recognition that he felt he deserved, and they flaunted it in a mean - spirited way, it could push him over the edge.
One possible reason could be a misunderstanding. Maybe there was some miscommunication in the past that led Naruto to believe his family didn't understand him. For example, if his family had different expectations for his future as a ninja compared to his own dreams.
One possible reason could be that he discovers some long - hidden family secrets that make him feel betrayed. For example, if he finds out that his family was involved in something unethical in the past. Another reason might be that he feels constantly overshadowed by his family's legacy and can't form his own identity within the family, so he decides to leave to find himself.
It could also be due to some external influence. Perhaps an enemy manipulated Naruto's mind in the fanfiction, making him see his family in a negative light. This enemy might have used some form of mind - control or false memories to turn Naruto against his family.