Some people write it for the drama. It adds a new and different perspective to the Naruto story. By having Naruto 'bash' his friends, it creates conflict, which is interesting to read.
Well, it could be a way for writers to explore different character arcs. Maybe they want to see how Naruto would react in extreme situations with his friends. For example, if his friends made a really bad decision that put the village at risk. Also, it might be a form of expressing their own frustrations with certain characters' actions in the original Naruto series. If they thought a friend character was being annoying or not acting right, they write a fic where Naruto calls them out on it.
One example could be a fanfiction where Naruto gets into an argument with Sasuke, who he considered a friend, due to a misunderstanding about Sasuke's actions towards the village. In this fic, Naruto might lash out verbally at Sasuke, expressing his disappointment and anger. Another could be a situation where Naruto has a falling out with Sakura over her continuous pursuit of Sasuke in a way that endangers the team. He might 'bash' her for not thinking about the bigger picture and only focusing on her personal feelings for Sasuke.
Another reason could be that some fans are so strongly attached to Naruto that they view any character who they think treats Naruto poorly as a target for criticism in fanfiction. Sakura, at times, did seem to take Naruto for granted in the original story. So, these fans write fanfictions to express their dissatisfaction with her character. Also, it could be a creative outlet for those who want to explore a different dynamic between Naruto and Sakura, one where Naruto is more assertive against her perceived flaws.
Some people write 'Naruto womanizer fanfiction' for the fun of exploring a different side of Naruto. It allows them to break away from his traditional heroic and somewhat naive character. They can create humorous and interesting scenarios where Naruto's charm is amped up and he interacts with female characters in new ways.
It could be a way for fans to express their own feelings about the unfairness in Naruto's original situation. They take it to an extreme with abuse in fanfiction to emphasize their point. For example, Naruto was already an outcast in the village to some extent, and the abuse in fanfiction is like a hyper - extension of that idea.
Some writers do it for the sake of creating unique and unexpected plot twists. Brainwashing Naruto goes against his usual character, so it can make for a very different and engaging story.
Some people write anti Naruto fanfiction because they want to explore different perspectives. They might not agree with the original story's direction or the character development of Naruto. So they create their own versions to satisfy their creativity.
People write 'Naruto Neglect Fanfiction' because it offers a different take on the original story. It allows them to explore how Naruto would develop if he faced neglect.
Some people write it for the sake of creativity. They want to explore different aspects of the Naruto universe that the original story didn't touch on. By making it dark, they can create a new and unique narrative.
People write 'naruto dead fanfiction' for various reasons. Some might want to explore different storylines that deviate from the original. Maybe they're curious about how the characters would react in such a tragic situation. It could also be a way to create more complex and emotional stories, as Naruto's death would have a huge impact on the entire 'Naruto' universe.
People write it because it's fun to mix two different and beloved fictional universes. Naruto and Leia are both iconic characters with their own unique traits. Combining them allows for creative and unexpected storylines.