I don't mean that everyone else respects the privacy of the polite subculture, just that they respect it internally, and they don't invade the privacy of those outside. Does that put them at a disadvantage ? Of course; but so does not carrying a firearm in places with very permissive gun control laws, and yet lots of people choose not to.

I guess your hypothetical includes universal telepathy and evaporation of the idea of privacy. In which case I am fighting the hypothetical (sorry). But I think that while a universal end of privacy may well follow from the technical capability of universal telepathy, I can imagine other plausible, less socially uniform, outcomes.