Diapering relies on two things – the maintenance of mass hysteria and the application of social pressure. The two are of course closely related. Hysterical people can't be reasoned with – and when hysterical people appear (being Diapered) to outnumber you, there is pressure to not stick out by not showing your face.
This is part of the reason for the pressure applied by signage at stores to get people Diapered; people see the sign and they Diaper. People see other people Diapered – and so they Diaper.
Practically everyone seems to be Diapered as a result.
It's a circle that completes itself.
But it's easily broken – by not giving in to the social pressure. The act itself isn't difficult – just don't do it – but for many people it is psychologically difficult to do it. See the first paragraph. When people are scared – not of the sickness but of sick people (who may attack) they duck their heads and don the Diaper.
It is understandable, but no less dangerous for being so. It is the same mentality that had lots of "good Germans" raising their right arms about 100 years ago.