I agree, and like Joey said we have a rating system. People just need to be diligent in using it so that it can become more effective.
Posting one-off threads of bad experiences tends to get lost in the noise and not everyone ever sees them. And most of the time it just turns into a he said-she said that people can’t draw any conclusions from.
I don’t think trying to create a hall of shame can be effective either since the scammers just reappear in different skins. While not the most satisfying answer, I think the rating system is as good as we are going to get.