There could be a family curse or some long - standing feud that led to their actions. Maybe an ancestor made a pact that now falls on them to betray their own son. Another possibility is that they were under the influence of some mind - controlling spell or potion, which made them act against their true nature and betray Harry.
Maybe they were forced into it by some dark magic or a powerful dark wizard. They could have been blackmailed into betraying Harry to save their own lives or the lives of others they cared about.
He might be extremely angry and confused. After all, parents are supposed to be the ones you can trust the most. He could start to question everything he knew about his family and himself.
One possible reason could be that in the fanfic, the author might twist the story to make it seem like his parents' actions had unforeseen consequences that affected Harry negatively. For example, their fight against Voldemort led to Harry being an orphan and having to bear a great burden from a young age.
It could be that his parents were trying to protect Harry in a really messed - up way. They might have thought that by 'betraying' him, like sending him away or making him seem like an outcast, they could keep him safe from a much greater threat. Maybe they knew some prophecy about Harry and thought this was the only way to ensure his survival. They might have made a deal with some dark force, believing they could outwit it in the end but ended up being seen as traitors by Harry and others.
One possible reason could be that he might feel abandoned. Growing up without them, he could resent the fact that they left him an orphan. He might think that if they were really so great, they would have found a way to survive and be there for him.
In some fanfictions, it could be due to a long - hidden family secret. His parents might have had a past that they were ashamed of or a debt they had to pay, and unfortunately, Harry became a part of that repayment which led to the perception of betrayal. They could have made a deal with a dark force before Harry was born, not realizing the full implications it would have on their son.
One possible reason could be a misunderstanding. Maybe he discovers some secrets about his parents that he misinterprets. For example, if he finds out they were involved in some dangerous or morally ambiguous activities in their youth that he doesn't fully understand at first.
One possible reason could be that he discovers some long - hidden family secrets that make him question his parents' actions or decisions. Maybe he finds out about some dark deeds in their past that he can't overlook.
One possible reason could be to explore different parenting styles in the wizarding world. Spanking, although a controversial form of discipline, might be used by some writers to show how Harry's parents could have dealt with difficult situations. Another reason might be for shock value or to create a unique and unexpected story within the familiar Harry Potter setting. It could also be a way for the writer to delve deeper into the characters' personalities and how they might react in a situation that involves discipline.
One possible reason could be that in the fanfiction, Harry might have discovered some dark secrets about his parents that made him feel betrayed. For example, if he found out they had some hidden and unethical magical experiments in their past.
Well, perhaps in the fanfiction, it shows that Harry's parents made a deal with Voldemort before their deaths. They promised to hand Harry over in exchange for something, like power or protection for themselves. But then things went wrong and they ended up dying, still leaving Harry feeling betrayed as he discovers this truth later. It could also be that his parents were actually working against the Order of the Phoenix all along and Harry was just a pawn in their real plan.