Ha ha. I remember my CO telling us that no one is supposed to talk openly about this policy. An older NSF who came back from studies to do his time queried if this was already outdated, given it was the 21st century. The CO gave the usual spiel about security during peacetime, etc, and even back then, we all thought it was a whole lot of BS.
Let me put this clearly, this policy persists because no one cares about confronting the 800 pound gorilla in the room. Not the NSFs doing their time, not the regulars in their jobs, and definitely not the scholars who have their plates stuffed with requests for policy papers which will never be implemented anyway.