Here is my reasoning: masks and face shields protect others by greatly reducing the amount of virus that might unknowingly be 'shared' by you. Their face coverings protect you by greatly reducing the amount of virus unknowingly shared by them. Think of it as 'mobile isolation'.
Add to that washing hands, giving each other safety space, and staying home if you are not well or know you've been exposed, and we can break the chain of infection. Slowing the spread of the virus buys time to research treatments and prevention methods, not to mention reduces the demand on currently overextended medical facilities and personnel.
Some day we will have faster, better testing and know when to isolate. Until then, mobile isolation is our best bet and, frankly, puts us each in charge of the risk to ourselves and others.
If you'd like to take part in our 'Masks are Patriotic' campaign, you can use any flag stickers you can find locally or you can get 10 stickers for $1 or 20 for $2 from us, Coffee Party USA: