Is a Shutdown an Overreaction?

From a blog by a guy named Mulligan. It got some angry response. The 90K is a bit hard for me to believe, based on the South Korean numbers:

                     Is a Shutdown an Overreaction?

60,000 - 80,000 Americans died from the 2017-18 flu, without exceeding the capacity of ICU beds. This flu was experienced around the world. Not a single country found it worth shutting down their economies in that situation.

In 2020 the forecast is that about 90,000 Americans will die from COVID-19, including some deaths due to insufficient ICU capacity. Shutting down "nonessential" businesses is now the norm.

This forecast comes from the Institute for Health Metrics and Evaluation IMHE at the University of Washington. Unlike me, IMHE are not amateurs with contagious disease time series. With "about 500 statisticians, computer scientists, and epidemiologists on staff, IHME is a data-crunching powerhouse. Every year it releases the Global Burden of Disease study...."

At what point is a reasonable person allowed to ask why the economic policies of 2017-18 and 2020 are so disproportionate?
Some people will say that the 90,000 would have been much higher without shutting down the economy. At what point can a reasonable person follow up with "Why were ALL of the 2020 costs, which were in the $ trillions, taken on the economic (and civil liberty) side of the ledger, and essentially NONE on the mortality side?"