Their concern is that 2.2 million number is calculated assuming 80% infection rate. If all that happens at once, the death rate will be much higher. If the fatality rate is higher then 1%, that number will be much higher.
At 1.23%, the current fatality rate in south korea, 80% of america would be 264,000,000 people, with 3,247,200 dead. If the healthcare system collapsed and the death rate climbed to 2%, the death toll would be 5,280,000. And the numbers go up from there.
Could america handle that many deaths? The american system, like all worldwide systems, relies on balance. Doubling the death rate would wildly unbalance the country both economically and culturally. The spanish flu killed roughly 0.64% of the american population over 3 years, and that created disruptions that were felt for years. Losing 1-2% of the population in a much shorter time period would be a catastrophic shock. We would survive, but not without consequences that would last for likely the rest of the decade. And until widespread testing is available, we have no way of knowing what the actual fatality rate will be. Assuming south korean numbers are correct, the disease would kill twice as many per capita then spanish flu did, and the effects would be unpleasant to say the least.
Look at shopping centers, there is a doubling of demand and all the shelves are bare for weeks. The same thing will occur if the death rate doubles for a year, crematories and cemeteries wont keep up, the economy wont keep up, and the waves from the impact will reverberate throughout society.
