They are testing more people. Another reason is that the heavy focus in younger people correlates to large protests in 32 California towns at cities. Protesters dont use masks correctly, especially since they wipe their faces, or uncover their mouths and noses just to speak or shout. Plus dense crowds in protests of people from all over the state and all over the nation.
The demonstrators also get hit with tear gas. The physical reaction is not just loss of vision from the tears. Runny noses and coughing are the result. I am ashamed that no one is making the connection with the demonstrations and the rise in cases. It is obvious with the average age of the population getting infected dropping to 35, down from 65 in March it was the result of the demonstrations.
These demonstrations had a double-barreled effect. Their results have the Marxists doing happy dances. They destroyed cities and their economy as well as giving the virus a big boost, thus prolonging its effects on the economy. In Seattle, for example, the costs of the riots have called for a payroll tax on employees to pay for it. This is targeting Amazon employees and will be an incentive for Amazon to move out of Washington State. The call to end police will permanently destroy cities and America as we know it.