It's the staff in bars and restaurants I feel sorry for.
There will be people with underlying issues and those who live with or have close contact with shielders.
Accepting and taking on a level of personal risk is fine, but this whole thing is very messy and puts people in the most unenviable and difficult circumstances.
It should be made possible in what are unprecedented circumstances, in post-furlough world, for people to make a conscientious objection to the obligation to work in situations where their own or the health or loved ones, is at risk.
Obviously, you would need to have some documentary proof of such circumstances, but people could get it. There needs to be creative and understanding human responses on this as the situation progresses.