I must say that I'm astounded at the amount of people who are still trying to make up any excuse for not having to wear a mask/face covering. Reasons such as people not knowing how to wear them correctly, so it's better not to wear them at all ... the government here in HK put out public service announcements on tv, and in newspapers, etc., for those who would find it challenging, but google provides good advice also. Reasons such as people touching their face more frequently ... train yourself not to! Reasons such as heat/glasses steaming up ... I live in a country with temps of 30'c+, and often close to 100% humidity ... I also wear glasses, and I can still manage to wear a mask if I need to go out. Stop making excuses!
And, the reasons I've seen people suggesting the delay until 15th June, such as the law needs to be written before it can be made compulsory ... there was nothing to stop the government from simply telling the public that for the health and safety of everyone, they highly recommend wearing face coverings with immediate effect, and it will be law from 15th June.
Also, the suggestion that people need to be given time to source the masks ... have many of the British public not noticed that there's been a pandemic going on for the past few months?! I think they've had more than enough time to source masks, or make their own face coverings, or simply use a scarf until they can source masks. Anything is better than nothing, and, if everyone had had the sense to wear them weeks ago, there would've been far fewer cases and deaths!