This isn't some guessing game where the consequence of being wrong is equal, whether you're wrong above or below the line.
If we're too cautious, zero additional deaths will occur and it would have wasted some money.
If we're wrong the other way, it would cause unknown numbers of deaths and would cost more money in the long run.
So in this situation of the great unknown, it's an easy choice of which way to be wrong on - we must be cautious.
I see your point, but "it would have wasted some money" is a little bit of a bigger issue than perhaps is being understood.
It's always a balancing act. We have thousands of highway deaths, but we don't set speed limits at 5 mph to counteract this. That would be an overreaction, and the damaged caused in commute, shipping, etc times would destroy the chance of having an economy.
We've basically voluntarily shut down a huge portion of our economy for the next month. We WILL see business fail over this. We WILL see people out of work, possibly unable to make their rent/car/utility payments. The pain point is going to be significant. It's not just "wall street". It'll be seen on main street too.
Maybe the death toll if we didn't would be SO huge that it was more than worth it. But we don't know what the death toll would be, and so you can't simply say that no reaction is an overreaction if it saves lives.
The optimal balance point is not zero deaths. That sounds rude as $&#@ to say, but it simply isn't. Just as we don't shut down our entire economy every year for the flu, which kills tens of thousands a year in this country alone.
I'm hoping we're making the right decision here. The downside is if we are successful in staving this off, the death toll will be low, and then a bunch of people will be saying "well we obviously overreacted because the death toll was so low" while others will say "if we hadn't done this the death toll would have been huge" and the problem is that we don't know which group is right.