There could be several reasons for the existence of such fanfiction. Firstly, it might be a form of creative exploration for those who want to test the boundaries of the characters' personalities. They may think that by putting Inuyasha in an 'abusive' role, they can dig deeper into his character flaws. Secondly, it could be an attempt to create a contrast. Since the original relationship between Inuyasha and Kagome is mostly positive, showing an abusive side can create a sharp contrast. However, this kind of fanfiction often goes against the general perception and liking of the majority of fans.
One possible theme could be power dynamics. Maybe exploring how Inuyasha's supposed abuse changes the power balance between him, Kagome, and Sesshomaru. Another theme could be the distortion of relationships. It takes the normal relationships in the original series and twists them into something darker.
Perhaps there are some who have a darker side to their creativity and don't fully consider the implications of writing about abuse. But this kind of fanfiction should not be encouraged as it goes against the positive nature that most fanfiction communities strive for.
Some people might create it out of a desire to explore dark or 'what - if' scenarios that are completely opposite to the normal relationship in the original work. It could also be a way for them to experiment with different types of conflict in writing, though it's not a very positive or healthy way.
There might be some 'Inuyasha abuses Kagome' fanfiction, but it's not something that is likely to be promoted or widespread. The original story is about their relationship growing and developing in a positive way, so this kind of negative and abusive take goes against the spirit of the original. However, in the vast world of fanfiction, it's hard to say for sure that none exists.
One possible reason could be a misunderstanding. Maybe Inuyasha misinterprets Kagome's actions or words. For example, if Kagome is trying to help a new character who seems to have a connection to the Shikon Jewel, Inuyasha might think she's being disloyal and thus betray her. Another reason could be some sort of dark influence. There could be an evil force that makes Inuyasha act out of character and turn against Kagome.
Some people might be exploring the darker side of human nature through these characters. They want to see how extreme situations can play out between Sasuke and Sakura.
Yes, there might be some fanfiction out there with such a plot. However, it's important to note that these often deviate from the original positive relationships in the Inuyasha series. Fanfiction can be a creative space where authors explore different, sometimes darker, storylines.
Some writers might create this type of fanfiction for shock value. They know that the original relationship between Rick and Morty has a certain dynamic, and by making it into an abusive one, they can get a strong reaction from readers. Also, it could be a form of expressing their own dark interpretations of power dynamics within the show.
Some people might create it just for shock value. They know that the original relationship between Goku and Chi - Chi is loving, so by creating something so opposite, they can get a reaction from readers.
One possible reason is that some fanfiction writers simply want to break the rules and norms of the original story. They see the established relationships as something to be toyed with, without considering the implications. Also, there might be a small subset of people who have some sort of personal issues or biases that they project onto the characters, leading to the creation of such a negative and untrue scenario in fanfiction.