Another reason might be related to a past event that Naruto unknowingly caused harm to one of the Team 7 members' families. Even if it was an accident, the emotional pain could make the affected member, and maybe the whole team, hold a grudge against Naruto. For instance, if Naruto's actions during a battle led to the destruction of a family's home, and a Team 7 member was from that family.
One possible reason could be a very different and perhaps unappealing take on Naruto's character in that fanfiction. Maybe the author made him overly cruel or out of character in ways that fans who love the original Naruto can't stand.
In some fanfictions, Naruto might be hated by his friends due to a misunderstanding. For example, if there's a false rumor spread about him being a traitor. Another reason could be his sudden increase in power that makes his friends jealous. Maybe he accidentally harms one of them during a training session and they hold a grudge.
It could also be due to a past event that Naruto unknowingly was involved in. Maybe something bad happened to Sarutobi's family or friends and he blames Naruto for it, whether it was Naruto's fault or not. For instance, if there was an attack on the village and Sarutobi lost someone close, and he wrongly believes Naruto had a part to play in it, he would start to hate Naruto.
It could create a rift within the overall story's world. Fans who love Naruto might not like this portrayal, which could lead to a divide among the fan base. Also, other characters in the story might have to take sides, either with Naruto or with the team that hates him, causing more conflict and drama within the fanfiction.
One possible reason could be a false accusation. Maybe someone spread a rumor that Naruto was involved in a heinous act, and without proper investigation, everyone turned against him.
One reason could be his power. His connection to the Nine - Tails makes him extremely powerful. In fanfiction, some in Konoha might fear this power and thus hate him. Another reason could be jealousy. Naruto becomes very popular and respected in the original story. But in fanfiction, some characters might be jealous of his achievements and turn that into hatred.
One reason could be some sort of betrayal he feels. Maybe he discovers a secret that makes him think Team 7 was never truly his team. For example, if he found out that the village leaders had some ulterior motives for forming the team that involved using him.
In some fanfictions, it could be due to outside influence. For example, an enemy might use some kind of mind - control or false information to make Naruto's friends turn against him. Also, Naruto's own actions that are misinterpreted can lead to this. Say he tries to protect his friends in a way that seems wrong to them at first glance, like using a dangerous jutsu near them to fend off an attack.
One possible reason could be a sense of being undervalued. Maybe he felt that his teammates didn't fully appreciate his efforts during the Wave mission. For example, if Sasuke got most of the credit, Naruto might feel pushed aside.
One possible reason could be a misunderstanding. Maybe they were misled by false information or an enemy's trickery that made them think Naruto was a threat at that moment. Another reason might be extreme pressure or a life - or - death situation where they thought sacrificing Naruto was the only way to save the rest of the team or complete a crucial mission.