The existence of Naruto abandoned crossover fanfictions can also be due to the difficulty of maintaining consistency. In a crossover, not only do you have to keep the Naruto universe rules intact, but also those of the other universe. For example, in a Naruto and 'Fullmetal Alchemist' crossover, the author has to make sure that the laws of equivalent exchange in 'Fullmetal Alchemist' don't conflict with Naruto's power - up systems. If it becomes too much of a headache to keep everything in order, the author may just drop the fanfiction.
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.
Another reason could be for shock value. By creating a scenario where Sasuke abuses Naruto, the writers can attract readers who are interested in seeing unexpected and controversial plot twists. But this kind of fanfiction often goes against the general spirit of the original Naruto series which focuses on friendship, growth, and redemption.
It could also be a way to explore alternative storylines. For example, if Sakura rejects Naruto, it can open up new paths for both characters. Naruto might have to find love elsewhere or focus more on his Hokage dreams without the distraction of a romantic relationship. And for Sakura, it can show her independence and her own journey of self - discovery outside of a relationship with Naruto.
These fanfictions exist because many fans like to explore alternative storylines. The idea of Naruto being banished adds a lot of drama and conflict to the story. Hinata's relationship with Naruto in these scenarios allows for a deeper exploration of her character, especially her loyalty and love for Naruto.
Well, it's hard to specifically name a particular 'Naruto abandoned crossover fanfiction' as there are so many out there. However, often when an author tries to cross Naruto with a Western - style fantasy world, they might abandon the story. Maybe they realize later that integrating the Naruto universe's ninja system with a completely different magic system is more difficult than they thought, and they just give up halfway through writing the fanfiction.
They exist to add more drama and tension. Hermione is a beloved character, and putting her in a life - threatening situation amps up the emotional stakes for the readers.
One reason could be that it's a very complex concept to write about. The Rinnegan has so many abilities and implications in the Naruto universe that it can be overwhelming for some writers. They start out with great ideas but then get bogged down in the details and can't continue. Another factor might be lack of time. Writers often have other commitments and can't devote enough time to fully develop their fanfiction ideas involving the Rinnegan.
Some exist to explore darker themes. Writers might want to show the resilience of a character like Frisk in the face of extreme adversity. For example, by having Frisk go through abuse, they can then show how Frisk overcomes it and grows as a character.
Some exist because it creates a really intense and dramatic conflict. Bellatrix is a very powerful and cruel character, and Hermione is a strong - willed heroine. Putting them in a situation where Bellatrix tries to break Hermione makes for a very engaging read.
They exist because it creates drama. The relationship between Clary and Alec in the original story has a lot of potential for conflict. Writers explore different scenarios where Clary might hurt Alec, either intentionally or not, to add more depth and angst to the story.