It could be related to personal losses. Perhaps he has lost friends or family due to the actions or inactions of the Olympians. For instance, if a friend died during a battle that could have been prevented if the gods had intervened properly. This would lead to resentment towards Olympus as it is the seat of the gods' power.
In some fanfics, Percy might hate Olympus because of the way it represents a hierarchical and often unfair system. The gods have so much power and privilege while the demigods are left to do the dirty work. For example, they are sent on dangerous quests with little real support from the Olympians. He could see this system as corrupt and thus come to hate Olympus.
Maybe he's tired of the gods' constant interference and manipulation in his life. They often use him for their own purposes without much regard for his well - being.
Maybe Naruto, as a character with his own set of values and storylines in the original Naruto universe, clashes with the concepts often presented in Olympus - related fanfiction. For example, the Naruto world has its own unique power systems, cultures and ethics which might be very different from what is typically found in stories related to Olympus.
One possible reason could be a misunderstanding. Maybe Percy accidentally disrupted one of Artemis's hunts or sacred rituals in the fanfic. Another reason might be that some prophecy or fate in the fanfic's made - up world has pitted them against each other. For example, if there's a prophecy that Percy's actions will somehow limit Artemis's power or freedom in the future.
One possible reason could be that Percy feels betrayed by the Olympians first. Maybe he discovers some dark secrets about them that make him lose faith. For example, if he finds out that they have been using demigods unfairly in their battles or politics.
Well, one reason could be that fanfiction often takes creative liberties that might distort the original relationship between Poseidon and Percy in the official story. It could be that Poseidon is a very complex character in the original, and fanfiction simplifies or misrepresents him in a way that makes it seem like he 'hates' Percy in those fictional interpretations.
Maybe he accidentally breaks some ancient and unforgivable rule. For example, he could have uncovered a secret that the gods wanted to keep hidden and in their attempt to silence him, they banish him. In fanfiction, the writers often play with the idea of Percy's curiosity getting him into big trouble with the Olympians.
Maybe he feels betrayed by the Olympians. They often have their own agendas and don't always consider the well - being of demigods like Percy. For example, they might send him on dangerous quests without proper support.
It could be that in the fanfic's plot, the Weasleys have some actions that go against Hermione's principles. Say, they might be involved in some pranks that have negative consequences for Hermione's studies or personal goals, and that's why she hates them.
Maybe he likes it because he has a deep connection with Annabeth in the original story and the fanfic allows him to see different interpretations of their relationship.
In fanfiction, the politics and intrigues within Olympus might be depicted in a way that makes Percy disgusted. The backstabbing and power - hungry nature of some of the Olympians could be too much for him to bear, so he hates Olympus.
Maybe she's jealous of Percy's popularity at school. It could be that he always gets more attention, whether it's from teachers or other students.