
I think it’s just a different pointview..
You saw it from the culprit perspective:: she just embarrassed by her past and being a coffee-shuttle isn’t that bad.
While the other see it from victim perspective:: I don’t even like her but the whole school now think I’m a fool who crazy in love
And also Amy wasn’t simply embarrassed by her past. She tried to make Shirone an outcast to the point that no one will believe him if he ever said something about Amy. She only stop because Shirone got attention from others in a different way.
And if Amy was a male character who make a girl character his bread-shuttle, people would still say something. I think it might be even worse than what Amy got.
I may not hate her as much as others. Like you said, she has character development, and I accept that. But I think it also wrong to say what Amy did is not so bad when it was clearly an act of bullying.

Well she got a kid surrounded by adult males who beat up that said kid, almost sexually assaulted him and sold him off or killed him if the kid didn't have the magic to throw them off. And years later she stayed unapologetic and made him an outcast so he would not be trusted even if he said the truth.
I think that's enough reason for people to hate her. Even without all these her character was damn annoying in the beginning.
Although afterwards, she became much more tolerable, If you just looked you would know that most of the people who are hating on her haven't read till the end.
I don't understand why people hate Amy so much. Like sorry she's strong and has personality. Sorry she's not some soft spoken fragile girl. Sorry that she felt embarrassed from her past as a delinquent and ended up making Shirone give coffee to her. Sorry that she's a female character with character development and not a hot male character. Sorry that she has ego because she's not only a high class noble and the only daughter of her family, she's rich, pretty, strong, and smart. Like geez. If she was a male character y'all wouldn't be hating as much!