A full face helmet has saved my face/chin twice in 40 years of riding on the street.
Too many times to count dirt riding. Before full face helmets,
we would install football face guards and wrap the opening between the two bars w/ductape.
I really don't care what people wear or don't wear while riding as long as they pick-up the tab for a get off.
And that includes loooong term health care... like drain bamage.