It might be due to jealousy. Peter is young and has a lot of potential. Some of the Avengers could feel threatened by his rapid growth and popularity, especially if he starts getting more attention from the public or from S.H.I.E.L.D. than they do.
Perhaps there was a plot twist in the fanfiction where Peter was brainwashed by an enemy and turned against the Avengers. After that, even when he was freed from the mind control, they still had a hard time trusting him again and showed hatred towards him.
Well, in some fanfictions, the Avengers might hate Peter because of jealousy. Maybe Peter's powers are so unique and he gets a lot of attention, making some Avengers feel overshadowed.
It could also be due to jealousy. Peter might be getting too much attention from the public or other superheroes. His youth and new - found popularity could make the more established Avengers feel overshadowed, leading to feelings of resentment towards him.
Well, it could be due to misunderstandings. Fanfics often play with the idea that Peter, being young and inexperienced, might accidentally cause trouble that the Avengers misinterpret as intentional. For example, he could be trying to help but ends up making a situation worse, leading to the Avengers' dislike. Another reason could be that some writers like to create drama by pitting characters against each other. They think it makes for a more interesting story if the Avengers have this negative view of Peter Parker, even if it goes against the more positive portrayals in the official comics or movies.
In some fanfictions, the Avengers might hate Spiderman due to jealousy. Maybe Spiderman's new - found popularity or his unique abilities make some of the Avengers feel threatened. For example, if he gets more media attention or praise from the public, it could stir up envy among them.
It could be that Peter's immaturity showed in a crucial situation. He might have been over - confident and tried something really risky without thinking it through. The Avengers, being more experienced, would be frustrated with his recklessness and thus yell at him. They want him to learn and grow, but his actions might have been too much to tolerate at that moment.
Maybe he thinks it distorts the real story of the Avengers. Fanfiction often takes the original story and characters in unexpected directions, which might not sit well with him.
Well, it could be that Jarvis hates the Avengers fanfiction because it sometimes misrepresents the characters. He has a certain understanding of the Avengers based on his interactions with them, and when fanfiction distorts those personalities or relationships, it might be off - putting to him. For example, if a fanfiction makes Iron Man act completely out of character, Jarvis, who has worked closely with him, would not like it.
Maybe he doesn't like how some fanfictions misinterpret his character or his relationships within the Avengers. Fanfictions can sometimes take wild creative liberties that might not sit well with how he sees himself.
Maybe he thinks fanfiction distorts the real image of the Avengers. He's a proud and complex character who might not like how some fanfiction writers portray him or his team.
Maybe it's because of some past misunderstandings or conflicts that haven't been resolved.