I don't think there's one available so I'll have a go instead. The stats in Australia indicate that 30% of admissions to hospital Intensive Care Units for Covid are the unvaccinated. The unvaccinated are 1% of our population, which in my simple mind indicates if you are unvaccinated and get Covid you are much more likely to get very very ill and possibly die. So, like you FF, I have trouble working out why people take the risk.
However, those stats also indicate very clearly that the vaccine works to minimize the disease, not prevent it. So you are able to be infected by a vaccinated person or an unvaccinated person. The best measures to protect yourself are hand hygiene and masks. While I would love to punish those taking the very selfish path of refusing to be vaccinated, I think the fact is Covid will be with us for probably 10 years (with various mutations) so we have to be as cautious as we can but get on with our lives. In summary, while personally I don't like the idea, I understand cruise lines beginning to allow the unvaccinated to sail.
Bear in mind, these are the ramblings of a very unrenowned pharmacist. 😁