But is there really ever a "valid reason" for refusing to wear some form of face covering? If there is, by inference there is then a "valid reason" for an asymptomatic shopworker to potentially infect dozens if not hundreds of people just because they don't want to wear a mask.
If you won't...
By how much could the spread of the virus have been mitigated if Boris had used the introduction of the new lockdown to withdraw his shopping list of exemptions from wearing face coverings in shops and on public transport?
I have noticed an increase in selfish individuals refusing to wear masks...