Positive interactions trump negative interactions when your goal is to encourage lasting change.

I don't know why you're being downvoted, shame is one of the most powerful motivators that exists in humans; I'd put money on it being the most powerful. People who are loudly disagreeing don't understand that "shaming (v.)" doesn't always equate to shame actually being felt in the target of said shaming. The act of shaming loses a lot of effectiveness when you can find a community of people who will tell you that it's not actually shameful and that, "no actually the people shaming you are wrong" because those people will suddenly be your best friends. This can be good thing, homosexuality, or bad thing, nazis. And the internet has made every one of those communities 0 distance from everyone. It's why people who try to employ it cut you off from your support networks.

Shame is so effective when it actually lands that you can never fully deprogram it -- I will live with my Catholic guilt for the rest of my life.

It ends up leading to "word-inflation" where you have to keep shouting louder, stretching the truth to be acknowledged. The word "racist" changing meaning over the last 30-40 years is a great example.

Shame can't fight lawyers and handcuffs.

Nope, shame is ineffective as a tool for change. More often people shut down or ignore you if you attempt to shame them than actually make the change you want. Besides, it's frequently just about vengeance anyway. Shame is really hate of other, for the most part.

As a tool for oppression however, yes it's quite effective.

Because everyone makes mistakes, if you antagonize someone they are less likely to care about you and feel more obligation to protect their own.