I think we're confusing outward display of "shame" and "embarrassment" or whatever else in that general genre and inner experience. These people are DRIVEN by the internal experience and anxiety about fear, embarrassment, shame, inadequacy, etc. and it explains all of their actions very well.

They're blustery cowards. This is how that kind of person acts.

They're not shameless, they're overflowing with shame and acting out because of it. Leaders and supporters.