More precisely, why they were forced onto faces.
Last year around this time, it was necessary to create the image of a "pandemic" and more than that, the image of near-universal agreement that there was a "pandemic." Both were achieved by forcing practically everyone to walk around with a thing around their faces formerly seen only on the faces of the mentally ill – outside of surgical suites. It gave the visual of a national Hantavirus ward, sans the Hantavirus.
And of course, sans the bodies stacking up like cordwood. "The cases! The cases!" were stacked up instead.
Of course, the problem with that was – and remains – that there are still a lot of people who can distinguish between a "case" and a corpse. These people could see that the bodies weren't stacking up like cordwood, that hospitals were not overflowing with dying supplicants.