So in every single publication just about every first century "Christian" had beards, this includes Jesus. The watchtower proclaims to be a footstep follower of Jesus. So if anyone is "stumbled" by a brother wearing a beard, there is one simple explanation. I wear a beard because I am a footstep follower of Jesus, and point out the many publications that illustrates not only Jesus, but also his apostles wearing beards.
There is no argument to be had here, the watchtower cannot simply forbid beards if they do not follow by example. Besides, the only reason they try to forbid beard wearing is because they want their salespeople to look clean cut on the outside. Fortunately most people realise these days that this is a false presentation to try and recruit more slaves to the watchtower.