What is wrong with it, is that because you do not need proof of vaccination, you will have all the unvaccinated anti-maskers and anti-vaxxers pretending to be vaccinated. In addition to that, a lot of them will buy/print fake vaccination cards, just like they did with their fake mask exemptions. The honour system requires people to have honour. And they do not have any honour. “My question is: should vaccinated, maskless people worry at all about an unvaccinated person possibly infecting a vaccinated person?” Unvaccinated masked people should worry about being infected by unmasked unvaccinated honourless K’Pekts who are pretending to be vaccinated.