But surely that should have been an aim from Day One (or at least from the day that the government decided it would try to supress the virus rather than allowing it to spread). If face coverings are so effective (and seemingly vital) in preventing spread why did it take more than three months to introduce the measure and ten days from the announcement of the requirement until it came into force? Compare this to the four hours notice people had who were either in Spain or about to set off there, telling them they needed to take a fortnight off work when they returned and there is little wonder that the public's confidence in the government's handling of the crisis is not very great. There doesn't seem to be much joined up thinking.
I don't think it's as clear cut as that. There are some
possible reasons for not bringing in masks earlier:
1) The evidence for how useful masks are is weak, and the view has shifted from "not worth it" to "worth it"
2) The more people interact closely the more useful they are, so they are more useful now than before (not really the case in a grocery shop though)
3) There is now little concern that people will divert PPE from where it's really needed unlike a few months ago
4) The government really, really, didn't want to have to make people do this but now they think it's necesary
There's also a difference between bringing in a new law to mandate masks, and adding Spain to a 'black-list' using an existing law.
And if they had brought a mask rule in at zero notice it would have left people without access to a mask a bit stuck.
So far as I know they didn't tell people that they
shouldn't wear masks for another 10 days and then start wearing them once the law came in, though clearly many people did so.
I think there
are things to criticise about the way the government has handled things. If not bringing in masks in on day 1 of the lockdown is one, then they need to share the cricitism with many other countries.