What you are suggesting is that school bullies would simply cease to be bullies when you show them the error of their ways. Alas, that's not how the World works.
The only way to get to people like that is to hurt them, either physically, mentally, economically or socially. That's what we're doing as a collective by changing norms so that it's no longer considered acceptable to beat people up for being <insert whichever unique attribute you want>.
Doing that will result in conflicts. Sometimes those conflicts will escalate into violent ones. As a single person it's often not viable to proceed into that territory alone, and so it's better to widthdraw from that society.
