Nobody has the right to hurt other people by hitting them kicking them, calling them names, spreading rumours about them or by doing anything else which is intended to be upsetting.
Bullies try to justify their actions by saying that it is their victim's fault for being different. They may pick on someone who is tall or small, or fat or thin, or wears glasses, or has a different accent, or another religion, or is shy or clever, or good looking, or disabled or ..._Any excuse will do, and if there is no real difference then the bullies will invent one.
If this is happening to you tell yourself that it is not your fault, and that it is the bullies who need to change, not you.