Perhaps she has her own vision of their relationship and doesn't want it to be influenced by the often - strange and varying ideas in fanfiction. Fanfiction can be full of outlandish concepts that she doesn't want to be part of. She wants to preserve the unique and special nature of her relationship with Edward as it is in real life.
One reason could be a shift in the story's setting. If the fanfiction is set in a different time or place, Bella's values and interests might change, leading her to not like Edward. For instance, if it's a modern - day setting with different social norms, she may find Edward's old - fashioned ways off - putting.
Another reason might be Edward's overprotectiveness. He could have made a decision for Bella without consulting her first, like preventing her from seeing a friend. This kind of controlling behavior could make Bella feel frustrated and end up in tears.
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.
Another reason might be that the fanfiction is set in an alternate universe where their relationship has some fundamental differences. For instance, if the vampire - human dynamic is changed in that particular fanfiction, Bella might avoid Edward because she is afraid of the new and unknown aspects of their relationship.
Some writers might create 'Edward is abusive to Bella' fanfiction to explore the darker side of human nature and relationships. They want to see how the story would unfold if the relationship had a negative turn.
One possible reason could be that some fans want to explore a different dynamic. In the original story, Edward and Bella are in love, but in this fanfiction, perhaps the writer wants to show a more complex relationship where Edward hates Bella. Maybe it's to add more drama or to explore an alternative storyline that goes against the typical romance.
One possible reason could be that Bella discovers a different side of Jasper that she finds more appealing. Maybe Jasper shows a deeper understanding of her in some aspects that Edward lacks. For example, Jasper's past experiences might make him more empathetic towards Bella's own struggles in a way that Edward, with his own set of vampire characteristics, doesn't quite get.
Perhaps it's related to his internal conflict regarding his relationship with Bella. He might be feeling so much guilt about bringing her into the dangerous vampire world that he has a moment of self - destructive behavior where he almost kills her. Or it could be a plot device used by the author to create more drama and tension in the story, making the readers more engaged as they wonder how Bella will survive and how their relationship will recover from such a traumatic event.
One possible reason could be his over - protectiveness. Edward might think that marriage would legally bind Bella to him and he could better protect her from the various dangers in their world, such as other vampires. He may believe that as his wife, he could keep a closer eye on her.
One possible reason is that the writer wants to explore the psychological aspects of such an unequal relationship. How would Bella feel, being in a position of slavery? How would Edward handle this extreme power? But it's important to note that this concept is quite controversial and not in line with the general positive tone of the 'Twilight' story.