When you feel shame it's because you accept external judgements. If you didn't accept those judgements then you wouldn't feel shame, you'd just be angry. Accepting external judgements is healthy and necessary because our self-worth is derived from our perception of how other people view us.
Like any tool, shame can be misused. But, as the article lays out, it's a necessary tool. It's also highly preferable to violence.
> In Not-Violent Communication Marshall Rosenberg considers shame (and guilt) to be one of the violent ways to change people's behavior.
Calling shame "violent" is dismissing actual violence.