Because he’s trying to stop the spread. Just because there’s not confirmed cases yet does not mean there won’t be. The goal here is to flatten the curve of the disease spread so that the health system isn’t overwhelmed.
Our medical system is set up to deal with Flu viruses that have .1% mortality rate, not a 3.4%. Plus this thing spreads easier and more widely, because people can walk around with it for longer and not show symptoms, than the flu we deal with every year.
So if the health care system gets overwhelmed that everyone having the normal daily strokes, heart attacks, serious car crashes, etc. are going to be less likely to survive because there are not enough ICU beds.
All of these actions are prudent and should have been implemented when we determine how virulent this strain of flu was.
He may be correct about the restaurants and bars, but saying the schools will be out the rest of the school year seems an exaggeration. The THING’S worst symptoms sound horrible.