Maybe it's related to his sense of independence. Naruto is used to relying on himself and having others touch him might make him feel like his personal space and autonomy are being invaded. He's always been on a journey to prove himself, and being touched could be seen as a form of interference in that self - discovery process.
It could also be related to his ninja training. He is always on guard and being touched might disrupt his focus or make him feel vulnerable in a dangerous ninja world. He has to be constantly aware of his surroundings, and unexpected touch could be seen as a threat to his safety.
It might be shown through his reactions. For example, when someone tries to touch him, he may flinch or move away quickly.
In his relationship with his mentors, it might change the dynamic of how they guide him. Instead of using physical gestures like a hand on the shoulder for reassurance, they would have to rely more on verbal communication. This could make the bond-building process more challenging as physical touch is often a way to convey closeness and trust in these relationships.
In a romantic relationship, it would be a major obstacle. His partner would have to be very patient and understanding. They would need to find other ways to show love and closeness, as physical touch is a common part of a romantic relationship. This could potentially slow down the development of a romantic relationship.
It could also be related to his jinchuriki status. The Nine - Tails' chakra within him might make him feel that being touched could lead to the unleashing of that power accidentally, and he's afraid of harming others or losing control. So, to avoid any such situations, he's scared of being touched.
It could also be that his siblings continuously rejected him and his ideals in the past. Naruto has always strived for peace and acceptance, and if his siblings constantly opposed him on these fundamental things, it might lead to his unwillingness to forgive.
One possible reason could be that their personalities don't mesh well in the context of the fanfic. Naruto might be portrayed as someone who values different qualities in a partner that Hinata doesn't possess. For example, if the fanfic focuses on Naruto's love for adventure and freedom, he may see Hinata as too reserved and home - bound, which could lead to a lack of romantic feelings.
One possible reason could be his past traumas. Naruto grew up alone and was often shunned by the villagers. Physical touch might remind him of the times when he was pushed away or bullied, so he has developed an aversion to it in fanfiction.
Naruto could be tired of the expectations placed on him. Everyone has always assumed he would be Hokage since he was a child. He might want to break free from those expectations and define his own path. He may feel that being Hokage is more about fulfilling others' wishes for him rather than his own true desires. So, he decides he doesn't want to be Hokage in this fanfiction.
One possible reason could be that Naruto has been mistreated by the villagers in Konoha for a long time. Despite his efforts to gain acceptance, if he's constantly faced with rejection or unfair treatment, it might lead to him not caring. For example, when he was a child, many villagers shunned him because he was the host of the Nine - Tails. This continuous negative experience could build up over time and cause him to lose his sense of loyalty to Konoha.