TW: Bullying
It's just something I discovered throughout the books and the movies. Bullying in Hogwarts was something that persisted through literally decades. And this is just so tragic. Hogwarts definitely needs a school counsellor.
Let us trace things to the earlier incidents...
[SPOILER ALERT!]
Leta Lestrange was bullied by several students in her school years due to gossip and the awareness of her half brother's death. She was an outcast, and she responded with a dark charm once. She became the one to blame because she lashed out to defend herself. Points were taken from her house. The students told on her. I know some of Leta's actions were selfish, but the tragedy she suffered from left quite a mark on her. She always felt like if her hands were unclean.
And does anyone remember Myrtle Elizabeth Warren? A.K.A Moaning Myrtle? In her student years, she was teased because of her glasses and acne, Olive Hornby is one of them. She is also the one to find Myrtle's body when Myrtle was crying in the bathroom due to her teasing. The even darker fact was that Myrtle remarked, "Nobody missed me even when I was alive. Took them hours and hours to find my body — I know, I was sitting there waiting for them." Decades after, she was only known as the ghost who haunts the girls bathroom on the 1st floor, and students still had the nerve to throw books at her for a game which she did not find funny.
In the Marauders Era, bullying occurred between the Marauders and Severus Snape. (Not to mention, Lupin was a bystander. He was still a kind person but he only shot a sympathetic gaze at the victim and did not take action.) When they were humiliating Snape in the chapter Snape's Worst Memory, the students around them simply watched, some even cheering them on. I don't know if the professors did anything back then, but if they were bullying someone for 5 years (or more), the rules are just not effective enough.
James Potter matured and changed his ways of course, which was a good thing, but the damage is done. Whatever great deed he does, it does not excuse him from being a bully. As for Severus Snape, of course it is painful to see the person you love, fall in love with the one who bullied you throughout your school years. It's hard to say, but sometimes, what happened in the past just won't affect the bullies because their mindset is just like that, and they can continue their normal lives, even becoming successful...While those who were bullied were left with scars. However, it also does not excuse Professor Snape from bullying Neville Longbottom. See? The cycle repeats itself.
In the series, it's mostly the Golden Trio vs Draco Malfoy. And about Draco Malfoy, well...He also reformed in the end, and he's also a deep character like all the HP characters, but it does not excuse him from all the bullying he did for 6 years of his school life. Insulting muggleborn wizards? That's basically being racist in the wizarding world. I know he became a troubled individual in the 6th book, even Harry noticed that he doesn't even abuse his prefect powers anymore, but again, his actions are not justified. He is very much a coward, afraid to kill Dumbledore but also wants to kill him because it's Voldemort's orders, and even refusing Professor Snape's assistance.
And here's something I might also post separately:
Luna Lovegood was also bullied in the books, but this aspect was slightly neglected in the movies. Her housemates stole her possessions, she was judged just because of her quirks and beliefs. Before meeting the Golden Trio, Ginny Weasley was probably the only friend she had. But even Ginny calls her "Loony Lovegood" as a joke sometimes (Maybe Luna is okay with Ginny calling her that? In the movies, she seemed unaffected by how the other students perceive her, but in the books, she got annoyed when Hermione kept disregarding her beliefs, and won't let anyone insult her father's work. Despite being quite extraordinary, she is still very much a person with feelings, who can be lonely at times, and desires friendship.
To conclude (not meaning for this to sound like an essay, but...) Bullying in Hogwarts had been occurring for decades, yet most clashes were resolved hastily by professors, and there were many bystanders. Hogwarts should really hire a school counsellor, since not much bullying was actually dealt with and solved from the roots of the problem. Action was taken, but it was not enough. Doing a bit of calculation, then you can see that it's been almost a century. Almost a century of bullying. Bullying is mostly encouraged when no one reports, and there were many bystanders who just marvel at the show. Then they clap.