Because it's a terrible policy prescription. If natural immunity is acceptable, what proportion of the unvaccinated-uninfected population will just take the risk? Half? More? Millions of people will just (continue to) take the risk, get sick, go to hospital, and die (in decreasing proportions), incurring substantial personal and social costs along the way. Accepting only vaccination as evidence of protection reduces…
To reply as the devils advocate to this comment, what is the tolerance to social costs that society is willing to bear? Also why would one segment of society have to do something that it doesn't want e.g. not bear risk if they want to? Should we tell people to get their BMI under 25 too? Overweight and obesity are going to cost much more in increased healthcare costs than COVID will in the coming decades (pls prove m…
A policy that accepts infection-recovery as equivalent to vaccination unconditionally and removes most/all other restrictions could result in lots of those social costs over a very short period of time, much shorter than the timescale on which resources can adjust. So much so that resources become exhausted, and the costs compound from merely high to truly awful. Personal choice resulting in an impaired standard of care for unrelated people in need for unrelated reasons should probably be discouraged or proscribed.
Once the risk of resource exhaustion is eliminated, a policy that's less than a full-court press for vaccination might be reasonable. But that risk is primarily determined by the size of the covid-naive population, which can only be reduced by vaccination or infection...