Because being raped by a teacher is a short-time thing and it's only 1 person. And it is also very easy to combat this - like literally go to any other adult and tell them about it and they will bury that teacher under the prison. It is kinda different when you are getting bullied by the same person as her brother, except there are like 5 of them, and anyone who tries to be on your side is automatically ostracized, so they pretend to don't see it or they even take part in it. And by bullying I don't mean just saying mean words, it also beatings, getting your stuff stolen, placing sharp object in your shoes/seat, being ordered around to do stuff, being striped naked, et.c.. And you have to deal with that like for 4+ years. The thing is that when you are being harassed by a collective you start to question you sanity. When you have a problem only with a single person nothing of that happens. It is their sheer length of it and the number of people that gets you.