But those users would be left alone in their pride in the put-up-or-shut-up model, because everybody else would see the mistakes of that user and abandon them. So the shame doesn't have to be effective for the individual, it just has to convince the majority that the user is in the wrong.
Right. To put it another way, this "put up or shut up" system, in my mind, isn't even really there to convince the person who got moderated that they were in the wrong. It's to convince the rest of the community that the moderation decision was unbiased and correct.
These news articles about "platform X censors people with political views Y" are about generating mass outrage from a comparatively small number of moderation decisions. While sure, it would be good for the people who are targeted by those moderation decisions to realize "yeah, ok, you're right, I was being a butthole", I think it's much more important to try to show the reactionary angry mob that things are aboveboard.
The most high profile, and controversial, "moderation" decisions made by large platforms recently have generally been for obvious, and very public, reasons.
But there are entire groups of users that not only don't feel shame about their activities, but are proud of them.