How do you propose that all of the at-risk people be found and quarantined? Should the National Guard be dispensed to go house to house nationwide? Who should they take into custody? The at risk or the not at risk? Where should they be taken? For how long?
Should household members not at risk move out? Maybe they could erect force fields inside their homes.

It seems that the easiest, least expensive, and least intrusive is an in general quarantine. As the intelligent and mature among us were self quarantining without being told and without whining - maybe you could take your cue from them.