But the outside world comes to them via goods and services, and all it takes in a barracks is for one person to pick it up and everyone is exposed.
Remember the Meningitis cautions?
10X that.
I also get that masks are not the protection we would like them to be, but this is what I tell people that point out the mask not helping much.
Sure, I would way rather go to the mailbox with shoes on, but if socks are all I have it's better than barefoot.