Indeed. Natural herd immunity it seems requires a much higher rate than is being postulated. Furthermore, the evolution has been over a much longer time-frame and accelerated by vaccines.
I'm told the Chinese are "incredulous" at our approach. Also given, as you say, we currently know so little about this specific virus, then the worry is that if you 'promote' getting a critical mass of hosts, then you also give rise to the possiblity of further mutation.