It could be that the fanfiction often puts Kakashi in situations that Naruto doesn't think are appropriate. For example, if the fanfiction makes Kakashi act out of character in terms of his loyalty or his ninja values. Naruto, who has a deep bond with Kakashi, might not like seeing his mentor misrepresented in such ways.
On the other hand, this could also be a chance for Naruto and Kakashi to have a more open conversation. Naruto could share his thoughts on how the fanfiction is misinterpreting Kakashi, and Kakashi could use this as an opportunity to understand Naruto's perspective better. This could potentially strengthen their relationship as they gain a deeper understanding of each other's views on how Kakashi is perceived in different fictional scenarios.
One implication is that it could lead to a decrease in the popularity of Naruto fanfiction in general. If the general sentiment is that there's enough, fewer people might be interested in creating or reading new fanfictions.
In my opinion, 'naruto has had enough fanfiction' may mean that the Naruto series has been subject to an overabundance of fan - made fictional works. Fanfiction can be great, but when there are too many, it can start to feel like the original Naruto concept is being drowned out. There could also be a sense that the creativity in fanfiction has become repetitive or is going in directions that don't really fit with the core of Naruto.
Well, there could be. Fanfiction writers love to explore unique and unexpected relationships. Since Naruto and Kakashi are both popular characters in the Naruto universe, some writers might come up with such a plot for the sake of creativity and exploring different storylines. But it's not a part of the official Naruto story.
Sasuke could be a popular character. He might be involved in the story in a way that either helps or hinders the situation where Naruto hurts Kakashi. For example, if Sasuke tries to stop Naruto from doing something stupid that would hurt Kakashi.
Another reason could be related to Kakashi's past actions. If there are some secrets or things Kakashi did in the past that come to light and Naruto doesn't like them, he could snap at Kakashi. Naruto has a strong sense of justice and loyalty, so if he feels betrayed or misled by Kakashi, his reaction could be to snap.
Maybe they think the fanfictions are starting to overshadow the original Naruto story. There are just so many different versions of fan - made stories that it's getting hard to distinguish the original from the fan - created.
Maybe Naruto decides to leave Konoha for a while in the fanfiction. He might feel that the village has let him down in some ways and needs to find himself outside of it.
Perhaps Naruto has grown weary of the excessive focus on Sakura in fanfiction. He might feel that other aspects of his life and the world around him are being overlooked. His own growth, his relationships with other characters like Sasuke, or his dreams for the village are not given as much attention as they should be in these fan - created stories. So, he's had enough.