Maybe Elena just doesn't like the way Bella is portrayed in fanfiction. It could be that she has a different view of the original Bella character and the fan - made versions deviate too much from it.
It's possible that Elena has some personal bias against the kind of stories that are typically written in Bella fanfiction. For example, if a lot of the fanfiction focuses on a particular ship or genre that Elena doesn't like, such as a romantic pairing she finds unappealing or a genre like angst that she can't stand. Also, it could be that the quality of writing in the Bella fanfiction she has come across is generally poor, which makes her dislike it.
In some fanfics, Bonnie might hate Elena because of jealousy. Maybe Elena always gets the attention of the male characters they both know, like Stefan or Damon, and Bonnie feels left out or second - rate in comparison.
Well, in some fanfictions, Hermione might hate Bella because their personalities are so different. Hermione is studious, logical, and a fighter for justice. Bella, on the other hand, is often portrayed as more passive and overly focused on her romantic relationships. Their different values and ways of approaching life could lead to Hermione's dislike of her in fanfiction.
Well, it could be that Paul has a different vision of the story's original plot and the fanfiction of Bella goes against that. He might be a purist when it comes to the original story and detest any deviation in the form of fan - made fiction about Bella.
In some fanfictions, Jacob might hate Bella because of the love triangle situation. He could feel that Bella has led him on or toyed with his emotions. For example, if she constantly goes back and forth between him and Edward, it can make Jacob bitter and resentful towards her.
In some fanfiction, Bella might hate Jacob because of his over - protectiveness. He can be very possessive and that could make Bella feel suffocated, leading to dislike.
Another reason could be the influence of other characters. There might be a new character in the fanfiction who convinces Bella that Edward is not who she thought he was. This new character could plant seeds of doubt in Bella's mind about Edward's intentions and actions, ultimately resulting in her hatred.
It could be that in the fanfiction world, Bella's mother has made some bad decisions in the past that directly affected Bella negatively. Perhaps she abandoned Bella at a crucial time, which led to Bella's hatred.
It could be because of a misunderstanding. Perhaps there was a miscommunication or an incident where the sister was wrongly blamed for something, and Bella held onto that grudge. Say the sister accidentally broke Bella's favorite item but Bella thought it was done on purpose, which then festered into hatred in the fanfiction world.
Well, it could be due to a number of reasons. Maybe in the fanfiction, Bella has some unique abilities or qualities that Elena lacks. And this makes Elena feel envious. Also, if the story portrays Bella as getting more attention from other characters, especially those that Elena values or is interested in, that would surely make Elena jealous.
Well, it could be that in the fanfic's storyline, Bella has had some bad experiences in the past related to intimacy. Maybe she was betrayed or hurt, which made her develop this hatred.