In some fanfictions, it could be due to political machinations. There might be a group within Konoha that wants to change the power structure. They see Naruto as a symbol of the old order or a potential obstacle in their path to power. So, they plot against him and betray him to further their own political goals. They might spread false rumors about him to turn the villagers against him.
One possible reason could be jealousy. Naruto is very powerful and some in Konoha might be envious. For example, some minor clans might feel that Naruto, as an outsider in a sense, gets too much attention and resources. Another reason could be fear. His Nine - Tails power is so immense that some might fear he could lose control and endanger the village, so they betray him to try and eliminate the 'threat' before it's too late.
One possible reason could be fear. Naruto is extremely powerful, and some in Konoha might fear that he could one day lose control of his power. Another reason could be political intrigue. There may be certain factions within Konoha that see Naruto as a threat to their power and influence. Also, jealousy might play a part. Naruto has achieved so much and has the love of many, and some might be jealous and thus plot against him.
One possible reason could be a misunderstanding. Maybe some false information was spread in the village that made Konoha believe Naruto had done something wrong. In fanfiction, things can be exaggerated and misinformation can easily lead to a situation of betrayal.
In these fanfictions, it might be related to the secrets Naruto holds. For example, if he discovers something about Konoha's dark past that certain people don't want exposed. They would then try to get rid of him by making him look like a traitor. Also, there could be external forces influencing Konoha to turn against Naruto, like other villages spreading false rumors.
Perhaps the fanfiction keeps rehashing the same tired storylines about Konoha. Naruto might be tired of seeing the same things over and over again, like always focusing on the village's dark secrets in a clichéd way instead of exploring new aspects of Konoha and its people.
One possible reason could be a misunderstanding. Maybe Naruto's newfound power is misconstrued as a threat. For example, if he discovers a new jutsu that the Konoha 11 don't understand, they might think he's going to use it against the village. Another reason could be the influence of an outside force. An enemy could manipulate the Konoha 11 into believing Naruto is a traitor, perhaps by forging evidence or using mind - control techniques.
One possible reason could be fear. Naruto has the Nine - Tails within him, and some in Konoha might be too afraid of its power getting out of control. They may not fully trust Naruto to keep it in check.
One possible reason could be political intrigue within Konoha. Maybe there are certain factions that see Naruto and Hinata as threats to their power. For example, they might be afraid of Naruto's influence due to his status as a hero and Hinata's connection to the Hyuga clan. Another reason could be a misunderstanding. Perhaps some false information is spread about them that makes Konoha turn against them.
One possible plot could be that Naruto's incredible power makes the Konoha elders or some jealous shinobi feel threatened. They might spread false rumors about him being a danger, leading to the village turning against him. Maybe they frame him for a crime he didn't commit, like a powerful attack on the village that was actually the work of an enemy they secretly allied with. This would make Naruto, who has always been loyal to Konoha, feel extremely betrayed.
One reason could be betrayal. If Naruto discovers that some in Konoha have been secretly plotting against him or have been involved in something immoral that goes against his values, he might forsake the village. For example, if there was a conspiracy to keep him from achieving his true potential for their own gains.
Perhaps the Konoha leadership made a bad decision. They might have thought that distancing themselves from Naruto would be better for the village's overall image. Or they were influenced by some elders who held grudges against Naruto's father and took it out on Naruto.