So what's the argument here? You don't like how we populated in areas?
He can't grasp that many many years ago, humans collectively decided that in order for survival, they injected a small form of the virus to build up an immunity rather than spread out and rebuild a city (which they would most likely succumb to the illness before anything meaningful was built) and avoid cattle, one of the most common sources of meat and protein back in the day.
The virus is one of the most transmissible virus in history, and being in proximity to another person places you at high risk. His solution I'm assuming based on where he's going with his suggestion of spreading out, is for the infected people, or the entirety of humanity, pack up their horses and carriages, children, food, and belongings, and travel out into the wilderness and survive on their own without any other human interaction.
While also understanding this was hundreds of years ago before modern medicine, medical instrumentation to study the virus, and many other qualities of life that people benefit from today.
I'm surprised you even waste your breath on people like this when you and I both know they won't have an honest good faith discussion. You've got more tolerance for this, that's for sure.