The idea that people in places without documented community spreading think they're currently surrounded by many infected people seems unjustified to me. I understand keeping out of harm's way, and don't blame people from practicing how it will soon certainly be, though.
So I'm not saying it won't happen (that a high % of encounters will be with an infected person), I'm saying that, right now, you simply can't cover up people showing up at the hospital that can't breath. I presume that will happen 5 or 7 days after they're exposed. I want testing as much as the next guy, but people entering the ER that can't breath is a reasonable, albeit slightly delayed, proxy.
Once the ER's start counting cases like this, you can back-up the clock by a week and get a reasonable estimate on the percent of the community that were infected a week earlier. I presume that will be a very, very small number at the time that the very first ER cases are reported. But in my case, AFAIK, the ER's aren't getting anybody like that, so I presume that if there are people walking around my geography that "have it", that percentage is vanishingly small. Again, I'm not licking grocery cart handles, but we planned to "just live our lives" until there was significant risk. Alas, our state has closed sit-down restaurants. So much for living our lives normally. We're done going out for a long time. It feels weird.