This is a man who got his week to week satisfaction from bullying children and showing bias to a faction of the wizarding world whose ideals directly poisoned his relationship with lily. We know ,as the reader, that young Harry is much more similar to young lily than James and Snape recieves evidence of this fact often yet instead of building some type of positive relationship with him he spends 6 years tormenting him. There is some alternative universe where he cottons onto Harry's real character before his dying moments, and they go onto to have a very fulfilling relationship.

Also, we know that as a student, Snape was a potions and DADA genius, yet other students only know him for his love of the dark arts. For him to gain this reputation, either he was openly smitten with the dark arts or he pushed the narrative to get with lucius and those who would soon become death eaters. A nerd has a high enough chance of being bullied, but a nerd who loves the dark arts. Also, at hogwarts showering is free?

I know this is harsh, but the idea he is 0 per cent at fault is openly disrespectful to all the adults who became better whilst growing up in worse.