The difference between Snape and James is that James grew up and Snape remained a bitter child. No matter what side Snape was on in the end, his actions cannot be excused. He bullied CHILDREN while he was an ADULT. That is not okay. He called his best friend a slur. He joined a group of people who were against people like Lily. He only changed sides when Lily was in danger. He only cared about Lily. Snape is a bully. There are no excuses to bully children. Especially while you're their teacher. That is not the role of a teacher. Teachers are meant to nurture and care for you not make you fear them so much that they're your greatest fear.
James realised his mistakes and amended them. There is no way Lily would have had anything to do with him if he didn't. He sacrificed himself for his wife and son. James was a brother to Sirius. He and his family took him in. James did make mistakes and did bully others when he was a child, I'm not going to deny that. But, he learnt from his mistakes. He matured into a better person.
Snape bad mouthed James to his son who never got to remember his father. That is not okay. Snape was an asshole. Snape was so bitter that he was ready for James and Harry to die so Lily would survive. So you think Lily would have wanted anything to do with Snape after that? I think not. Again, I would like to reiterate, Snape joined a, simply put, a violent hate group who were against people like Lily. Wtf was he thinking. Did he really think Lily would go running to him after that?!

















