“Where did the “6 foot rule” come from? Can’t possibly be scientific.”
Actually it came from the 1918 Influenza outbreak, as they didn’t have much to go on.
Since then the CDC has been too busy searching for microbes hiding inside gun barrels (to prove guns are an ‘epidemic’) to bother with trivial concerns like trying to preventing nation-crippling pandemics.
When your goal is to cripple a nation, prevention ceases to be a priority.