Oh, people tried. Have you forgotten Trump? People dragged up every awful thing he did...but he wasn't canceled. People pointed out the new awful things he was doing...didn't work. People invented other awful things that he didn't do...didn't work.

Why?

Because the people who supported him didn't care about that stuff. He didn't care about that stuff. Shame is a withdrawal of approval from your own tribe. Not in the tribe? You have no power to shame.

So, if you're in the king's tribe, you can shame him.

Otherwise, nope. You have to rely on other methods.

Kings, knowing this, draw their tribal boundaries narrowly. (C.f. Davos.)