For the kids safety, parents and community alike
Regardless of low mortality and mild manifestation of coronavirus in children, there are many children with underlying condition that will be in the high risk group.
Also considering demographics reality most of middle and high schoolers have parents and grandparents in 60+ group that is now in CDC stay home for preventive measures recommendation group.
These parents and grandparents live together with kids often in one household, many has lots of other risk factors at this age. Continued possible exposure of kids at schools put their caregivers at extreme risk for contraction and complications and possible death.
Kids can bring it home.
New CDC guidance says older adults should 'stay at home as much as possible' due to coronavirus
Early data suggests older people are twice as likely to have serious illness from the novel coronavirus, according to the CDC.
This ought to be top of mind for people over 60, and those with underlying health problems, such as heart or lung disease, diabetes, or compromised immune systems," Schaffner added. "The single most important thing you can do to avoid the virus is reduce your face to face contact with people."
https://www.cnn.com/2020/03/06/health/coronavirus-older-people-social-distancing/index.html