It could be that his new 'godlike' power has isolated him. People might be either in awe or afraid of him, and he may feel that he can't be close to others as before. So he acts coldly as a defense mechanism.
Perhaps he is trying to hide his true self. He may have a side of him that he doesn't want others to discover, like some special abilities or a different origin. So, being cold to everyone helps him keep his secrets and avoid getting too close to people who might figure him out.
Well, at first, people around him would be very confused and try to reach out. But Naruto would just push them away. Then, his former friends might start to get frustrated with his coldness. Some might even turn against him thinking he has changed for the worse.
One reason could be that Naruto has been through so much himself and he might think rookies are naive. He's seen the harshness of the ninja world and doesn't want to coddle them. For example, he had to grow up without his parents and faced many life - threatening situations early on.
His friends would be hurt. They are used to the warm - hearted Naruto, and his coldness would make them feel rejected and confused. They might try to reach out to him but be constantly rebuffed.
One possible reason could be a great betrayal. Maybe he discovers that someone he deeply trusted, like a close friend or a respected mentor, has been using him all along. This would shatter his trust and make him withdraw from people, thus becoming cold.
In fanfiction, Naruto is often loved by everyone because of his unwavering determination. He never gives up, no matter how tough the situation is. This trait is inspiring and makes other characters in the fanfiction world respect and love him.
In many fanfictions, Sasuke's possessiveness is tied to his deep emotional connection with Naruto. He might feel that Naruto is the only one who truly understands him. So, when Naruto spends time with others, Sasuke can get jealous or possessive. For instance, there are stories where Sasuke gets moody when Naruto is training with other ninja. He doesn't like sharing Naruto's attention. This shows his possessive side in a more complex emotional way.
It creates conflict. The rookies might be initially discouraged or resentful of Naruto's coldness. This can lead to them trying harder to prove themselves, which drives the plot forward as they strive to gain Naruto's respect.
Maybe in that fanfiction, Naruto's over - eagerness to be recognized could be misconstrued. His loud and boisterous nature might annoy people. For example, if he constantly interrupted others or pushed his ideas too hard without considering others' feelings, it could lead to dislike.