Why do adults say the answer to bullying is standing up to them or reporting them?

I understand that school bullies are going to be around as long as they are alive, but bullying can be stopped and prevented as long as there are people who are dedicated to take fair and firm action against those who bully on the victims' behalf. 90% of time, most bullies would feel fearful and powerless when their victims have the willpower and courage to confront and stand up to them. You know school bullies can be arrested, jailed, and charged depending the severity of the bullying.