So let's speculate about using shame and social pressure to get people to do what you want them to do. What do threats of cancelation get us?
Well we can make people do what we want if we threaten them. Anyone with kids knows that. But if that is all you have then they will revert to their old habits once the threat is gone. You need power to reinforce the punishments promised in the threats. So as long as you have power you can make people do what you want them to do and say what you want them to say. But what happens if you lose power? If that person does not want to do what you want them to do then they will stop. So you must retain your power in order to be able to shame or threaten others to get compliance.
What if you define what you want them to do in survival terms? In other words they have to do this or your group will not survive. Then retaining power is not just a want but a need. You have to retain power at all costs. Well gee nothing bad has come from seeking power at all costs, right? Ahh now we are beginning to see what happens when we rely on shame and cultural power to force people into compliance.
I believe these are the dynamics that turn people into that which they hate. It is how the oppressed can become the oppressors. If we do not find better ways to motivate others, then we will see more people turn into the monsters they once fought.