It's a fact that Rutherford didn't like beards, so eventually, the WT created a not written prohibition on beards. The same WT leaders make JW's believe that a brother with a beard was a spiritually weak person that allowed the Satan's World influences controlled his life. With that programation in mind, JW's men didn't want to be seen as spiritually weak people that allowed the corrupting influences of this system of things affected the congregation. BINGO!! The work was done. It was their "Christians trained conscience" that kept them away from beards.
Eventually, one brother here and another there realized the nonsense of this kind of reasoning and decided to grow a beard. What was WT next move?? The "stumbling block". They spent paper and ink making these brothers feeling guilt because they were making others(the weak ones) stumbling. First, the bearded brothers were the weak ones and know they were the stumbling blocks for the weak ones.
Since then the WT never has tried to correct the wrong point of view of the weak ones on this matter. Why?? Because they(the weak ones) make the perfect excuse that fills WT needs for control.