The objection to beards I suppose was when it still carried the idea that if you didn't shave you were a member of the great unwashed. The Wolrd Wars set the syle for minimal hair presence including being clean shaven. Militarism had no time for personal expressions in grooming when the demands of battle are focussed on obeying orders-- exactly as it is in the JW cult.
The really obvious symbolism of being clean shaven is the JW policy of cultivating the appearances of good religious people, if you look wholesome in a clean cut American way, then the religion looks attractive they think. Jesus condemned "appearances", whitewashed graves he called those who look clean and righteous but like Watchtower governing body policies, they conceal awful things.
By the way GB member Van Ambergh had a beard up until his death about 1947.