Until we know how this thing is spreading, we need all the information we can get. I'm not sure why this is so hard. You're not a dumb person, but you're making a dumb argument. Right now we need to know how fast this is spreading and where it has spread. We need to know nationwide. This helps direct critical resources and leaders adapt their response, especially locally.
This is the current situation. In two months when this has spread like wildfire, we won't be testing everyone anymore, just the most at-risk patients. But right now it's a pandemic that requires both medical treatment for the patient and an information/resource response at the local, state, and federal level. We need to know if we should start closing down universities and schools preemptively. We need business leaders to have the right information to tell their employees something (anything!) about how to respond and how to isolate. We need to know where to send the most facemasks, artificial respirators, oxygen, and other needed supplies.
On top of all of that, we still dont' have a good grasp at how this thing spreads. We have a solid theory (droplets) with a few loose ends (fecal, airborne, eye, GI, etc.) that need to be tied up. We also need to know if symptoms are necessary for it to be contagious (this is still developing in the literature despite what anyone in the media says) and we need to know the typical vs. complete incubation period.
