It's about making sure that infection of the population gets spread out over a longer course so that the health care system is not swamped at any one time. It was never meant to suggest that everyone stays home until the virus is gone.
Everyone who participates in daily American life is going to be exposed to the virus at some point. It's a matter of timing, and making sure that we do not all start dying of non-fatal conditions because we can't get into the hospital on one hand, and ensuring we don't plunge into a global economic depression on the other.