Because you make decisions based on false information.
Probably none of the data is actionable even at this point in time. From the story linked below, 96% of prisoners who tested positive had no symptoms whatsoever. This indicates that short of testing everyone (or a representative sample) we have no idea what the denominator is for cases, hospitalizations or deaths.
A city in Italy actually had "hug a Chinese" day, so there's that.
It wouldn't be out of the ordinary to find out that distinct populations have more or less susceptibility to a particular virus. But until we have better data, who knows?
I will also say, I think the idea of ramping up precautionary measures is stupid if the goal is to eliminate the virus. Only way that can happen is shutting everything down immediately and you need a high degree of compliance. However, if the goal was to flatten the curve, we've done fine. Hospitals have been able to handle it.
Now, if 130M additional people die from starvation this year and it's because of all of the shutdowns, we definitely overreacted. There's also this study that correlates 500,000 additional cancer deaths in the US during the great recession. Causation not established, but interesting nonetheless.