It could be a plot device in the fanfiction. Writers sometimes create conflict to drive the story forward. So, they make Molly Weasley hate Hermione to add drama. Maybe Hermione represents a new way of thinking or a new kind of magic that Molly doesn't understand or is afraid of. This can lead to Molly having negative feelings towards her.
Well, in some fanfictions, it might be because of a misunderstanding. Maybe Hermione's actions are misinterpreted by Molly. For example, if Hermione is too focused on her studies or magic research and seems to neglect the family values that Molly holds dear, Molly could start to dislike her. Another reason could be that Molly is overprotective of her son Ron, and she might think Hermione is too pushy or controlling in their relationship.
Maybe in some fanfictions, the writer wants to create conflict. Molly might be written to hate Hermione because of differences in their personalities or values. For example, Molly is very family - oriented and Hermione is more focused on academic and magical achievements. Their different priorities could lead to friction in the fictional stories.
Perhaps in the fanfiction world, there are some misunderstandings. Molly could have accidentally said or done something that Hermione misinterpreted. Maybe Molly made a comment about Hermione's Muggle - born status in a way that Hermione took as offensive, even if it wasn't meant that way. This could easily plant the seed of hatred in Hermione's mind.
In some fanfictions, Hermione might please Molly Weasley by showing great respect for the Weasley family traditions. For example, she could participate wholeheartedly in the preparation of family feasts, using her intelligence to follow Molly's recipes precisely. She might also use her magic skills to help around the Burrow, mending things or cleaning in a way that Molly appreciates.
Maybe Hermione made a mistake that Molly thought was unforgivable in the context of the wizarding world. It could be something related to magic use that goes against the Weasley family's values. For instance, if Hermione experimented with dark magic in a way that Molly feared could endanger her family or the wizarding community.
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.
Maybe Lily has a very different view of the characters. She might think the fanfiction misrepresents Hermione in some way that she doesn't like.
Maybe James has a very different view of the original relationship between characters in the story. He might think that fanfiction distorts the essence of the original story and characters, especially when it comes to Hermione. He could be a purist who only likes the original portrayal and doesn't like the various interpretations in fanfiction.
Well, in some fanfictions, Sirius might be depicted as hating Hermione due to misunderstandings. Maybe he misunderstands her intentions or actions. For example, if Hermione is shown as being too strict with the rules in a story, Sirius, who has a rebellious streak, could resent that.
In some fanfictions, Hermione might be portrayed as hating Ron to create a new and different plot dynamic. Maybe the author wants to explore an alternative relationship path for Hermione, or they could be trying to add more drama by having her oppose Ron, who she is typically friends or more with in the original series.
Well, sometimes in fanfiction, authors like to explore dark and twisted ideas. Maybe they want to create a contrast to the kind Molly Weasley in the original series. It could be a way to add drama and conflict to the story, even if it's a bit out of character for the Molly we know.