The JW's prohibition on beards is enforced just as rigidly in those countries where it is commonplace to see bearded men about in the community.
One such example is Papua New Guinea, where many - perhaps even most - men wear beards. They are certainly common in public life; most of the countries top business and professional men wear full beards, as have a number of their recent prime ministers.
It makes no difference to the JWs, though. When a man comes "Into The Truth", then off comes the beard!
If ever there was a purely man-made rule, this would have to be it.