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Moodyz "Relate to the teacher" you say...
Does that mean you got raped by your own mother too?
Those notes are supposed to give an insight to the thought proccess of the villain, to explain why he became like that, not justify it. Don't think that evert backstory are like the ones from shōnen mangas, where everybody and their grandmother get sad backgrounds so we feel sad for them and stop hating them.
Understanding someone doesn't neccesarily mean you need to like them, it simply helps you know why they became like that.