This is a good point. Policing bullying in school (when young) may work if one can catch it in the act but this bully behavior never stops in adulthood, it starts taking different forms. Being aware of bullies and not being affected by their actions helps but they will only find a different target.
I think the point the OP is trying to make isn't to police bullies, but to figure out the influences on the child to be a bully, and to correct for that, so that the kid doesn't bully in the first place.
Actually, sex education is an excellent metaphor here. Teenage pregnancy happens when you assume by not addressing how teen pregnancy happens, teenagers won't fuck. However, teenage pregnancy goes down when you give access to safe sex, robust sex education, and effectively take away the forbidden fruit of fucking.
Similarly, teaching kids how bullying functions and a robust environment that prevents the causal factors of bullying can cut down on the actual bullying behavior.
