One reason could be that he sees her intelligence and potential. Snape has always had a soft spot for those who are brilliant in potions and magic, and Hermione is top - notch in that regard. He might also recognize her determination and how she's often an outcast among her peers in a way, just like he was. So, he feels a sense of kinship and thus protectiveness towards her.
At first, Hermione might be suspicious of Snape's new - found protectiveness. But as time goes on, she starts to see that he has good intentions. Snape, on the other hand, gradually warms up to Hermione more and more, sharing his knowledge and advice with her.
In the fanfiction, it might be shown through Snape secretly watching over Hermione during dangerous situations. For example, in a battle or when she's being harassed by other students who are prejudiced against Muggle - borns.
One common scenario could be in the face of other students' bullying. Snape might subtly step in and stop the bullies without making it too obvious. For example, he could give the bullies extra assignments or detention, which would indirectly protect Hermione from their taunts.
In this fanfiction scenario, Snape may become protective of Hermione because she might be involved in some important magical research or discovery. Snape, being a knowledgeable wizard, realizes the significance of her work and decides to protect her from those who might want to stop or steal her ideas. Also, Hermione could be in the middle of a conflict between different wizarding factions, and Snape, for his own reasons, decides to side with her and keep her safe.
Well, in some fanfictions, Snape might be protective of Harry because he sees a lot of Lily in Harry. Lily was Snape's long - loved friend, and Harry is her son. So that connection makes Snape feel an urge to protect Harry from harm, despite their often - rocky relationship in the original story.
Snape might be protective of Draco in fanfiction because in the original series, Snape has a certain loyalty to the Slytherin house. Draco is a young Slytherin, and Snape could see a bit of his own past self in Draco. Also, Snape was tasked with some difficult and dangerous missions by Voldemort. He might want to protect Draco from getting too deeply involved in Voldemort's dark plans to spare the boy from a similar fate as his own.
Moony might be protective of Hermione because he has a strong sense of justice. In the wizarding world, Hermione is a Muggle - born, and she often faces discrimination. Moony, being a member of the Order of the Phoenix, is against all forms of prejudice. He would naturally want to protect her from any harm, whether it's from Death Eaters or just general bigotry within the wizarding community. Also, Hermione's intelligence and her role in fighting against the dark forces make her an important asset, and Moony would understand the need to safeguard such a valuable ally.
One reason could be that they see her intelligence as an asset. Hermione is known for her brilliant mind, and Slytherins, who value cunning and resourcefulness, might respect that. They could also recognize her strength in the face of adversity and be drawn to protect her as a way to show their own growth beyond the typical Slytherin - Gryffindor rivalry. In some fanfictions, a Slytherin might have a personal connection or debt to Hermione, which leads to their protective nature towards her.
Maybe it's because he admires her intelligence. Hermione is known for her vast knowledge of magic, and Charlie, who has his own area of expertise with dragons, might respect that. He sees her as someone worth protecting because she could contribute a great deal to the wizarding world, and he doesn't want to see that potential lost.