One reason could be redemption. Harry realizes that Snape has had a very difficult life and has been on the right side all along, despite his harsh exterior. Harry, being the kind - hearted person he is, would want to save Snape to give him a chance at a better life after all the sacrifices he has made for the wizarding world. For example, Snape's love for Harry's mother Lily was so strong that he dedicated his life to protecting Harry, so Harry might feel a sense of indebtedness.
Another reason could be for the greater good of the wizarding world. Harry knows that Snape is a very powerful and knowledgeable wizard. Losing him would be a great loss to the fight against the dark forces. Even if they have had their differences, Harry can see that Snape's skills in potions, dark arts defense, and his knowledge of the Death Eaters' plans are invaluable assets. So, to ensure victory over any remaining dark threats, Harry would save Snape.
One reason could be that he realizes Harry has a lot of potential and wants to nurture it. He sees that Harry is in a difficult position, being the target of Voldemort, and decides to help him despite their past differences.
It's popular because both Harry and Snape are very complex characters. Their relationship in the original books is full of tension and mystery. Fanfiction allows fans to explore different aspects of that relationship, like what if they had been friends from the start or if Snape had been more open with Harry about his past.
If Snape raised Harry, Harry would likely become a much more skilled potions master at an earlier age. Snape's knowledge and strict teaching methods would push Harry to excel in that area.
It would be extremely complex. Harry might initially be in disbelief and struggle to accept Snape as his father. Snape, on the other hand, would probably be very strict but also deeply protective in his own way.
Well, it's mainly because of the complex relationship between them in the original series. Snape's actions towards Harry were often ambiguous. Fanfiction writers like to explore the idea of Snape having deeper, loving feelings for Harry as a way to add more depth to their relationship. It also gives an opportunity to rewrite some parts of the story from a different perspective.
One possible reason could be that fanfiction often takes creative liberties that may distort the complex character of Snape that J.K. Rowling created. Snape has a very intricate backstory and personality in the original series, and fanfiction might simplify or misinterpret it.
One reason could be to add a shock factor. It completely changes the expected family relations in the original story. Another reason might be to explore Snape's character more deeply. If Harry is his son, it gives a new perspective on Snape's actions and emotions towards Harry throughout the series.
Well, in the Potterverse, Snape is a very polarizing character. Some fans love him, and some don't. Those who don't might be more likely to write him as a bully in fanfiction. It could also be that they want to create an 'underdog' situation for Harry. By having Snape bully him, Harry becomes more of a hero when he stands up to it or finds a way to deal with it gracefully.
It's popular because it offers a different perspective on the relationship between two very complex characters. People are intrigued by the idea of these two characters, who had a lot of animosity in the original series, coming together as mates.
One reason could be guilt. In the original story, Snape had some complex feelings towards Harry's father. By protecting Harry in fanfiction, he might be trying to make up for the past. It's like he's trying to right the wrongs that were done to Harry间接 because of his relationship with James Potter.