The concerns of retailers over the suggestion that all shoppers should wear face masks when in stores is understandable.
They have seen shoppers become angry with each other over the disregarding of social distancing guidelines and don't want to have to referee disputes over the wearing of masks - and nor do the police.
People should wear masks to protect each other in closed environments and health safety should always be paramount. Making the wearing of masks mandatory removes any doubts on how to behave responsibly. If retailers oppose the move, they could find that a substantial number of shoppers will go elsewhere.