Well, in the wizarding world, he was focused on more important things like fighting dark wizards, protecting his friends and family, and dealing with the politics of the magical community. Fanfic was just something that happened outside of his main concerns. It was like a side - show that he didn't have the time or inclination to pay attention to. He had enough on his plate without getting involved in the fictional creations of his fans.
One possible reason could be that fanfiction often takes the original story in directions that might not align with the author's vision. J.K. Rowling, who created Harry Potter, had a very specific world and story in mind. Fanfiction can sometimes distort or change elements of that world in ways she might not have intended. Also, from a legal and copyright perspective, it's a bit of a gray area, and she may have wanted to distance herself from it to avoid any potential legal issues or confusion about what is 'official' and what isn't.
She might have ignored it because she doesn't like the idea of others creating unauthorised stories about her.
It could also be for the sake of creating a different plotline. Writers might want to explore how Harry would develop without the support of his father figure. So they make James ignore Harry to see how Harry overcomes the challenges on his own.
Maybe he just didn't care much about fan - made stories. He was so used to his own real - life adventures in the wizarding world that fanfiction seemed unimportant to him.
Maybe he doesn't even know about fanfic. He's focused on his real - life superhero stuff and doesn't have time to explore what fans are writing about him.
It might be because of a misunderstanding. In some fanfics, a false rumor could spread about Harry. Ron and Hermione, believing it to be true, might decide to distance themselves from him. Say, there's a rumor that Harry is involved with dark magic in some way, and they, being the 'good guys', think they need to stay away.
One possible reason Albus has haters in fanfic is that fanfic writers sometimes like to explore darker or more complex sides of characters. Albus, being a complex figure already, might be depicted in ways that are unappealing to some fans. For instance, if a fanfic delves into his past mistakes and over - emphasizes them, or if it shows him as being power - hungry in a way that doesn't seem in line with his more positive aspects in the official story. This can lead to a negative perception of him among some readers of fanfic.
It could be that the characterizations weren't right. If the characters act out of character, it can disappoint fans. Also, the writing style or the pacing might not have been appealing.
It could also be a matter of miscommunication. In some fanfics, Batman and Wonder Woman may not communicate well. Batman is often a man of few words and his actions can be misinterpreted. He might be so engrossed in his own investigations that he doesn't take the time to listen to Wonder Woman, giving the impression that he's ignoring her. This can add an interesting layer of conflict to the fanfic story.
One reason is the rich and detailed wizarding world created in the original series. It gives fans a vast playground to explore in fanfics. For example, they can create new adventures for Harry and his friends at Hogwarts.