I feel the Beard for the man has to do with manhood in the purest sense. Leaving the beard shows maturity, which usually is part that happens after a relationship or multiple relationships. It is associated with wisdom, and usually naturally feels after fatherhood.
I've seen this natural fatherhood need and after fatherhood with men, and also with men that crave fatherhood or relationship connecting. The reality is that naturally wearing a beard should happen after the marriage and after the relationship and after the fatherhood, not before, because the face of a man is supposed to be attractive for a woman. And the attraction lies under not covering it up totally.
The relationship between the headscarf and the beard feels to my opinion kind of corrupt, because you can not see the true beauty of someone, it makes someone more mature than their actual age is. These theories happen after a relationship that is solid and proven to withstand the test of time.
I can understand the fashion small beard that makes the guy more mature. But the long beard that symbolizes wisdom and elderly and fatherhood that happens in the alternative culture only leads to less maintained face and you have to take care of a lot of hair on your face. The truth is, under the beard is still the babyface with a lot of men that want to grow a long beard. The angry faces usually don't need a beard and usually take a small beard instead.
So the need for maturity lies in the real experience of a real relationship and a real marriage and a real fatherhood. After that it makes sense to wear a longer beard if you still want to, but you might find out you actually want to look young your whole life!
And anyway, that someone like an Example or Role Model did something in the past, doesn't mean that everyone has to immediately do the same, especially because it is a (self) sacrifice. Like the Buddha shaved his head as a way of transformation, doesn't mean that a female Buddhist should do the same! They can maximum cut their hair a bit, but not shave it!
As a woman I like what looks natural according to your real life experiences and age feeling:
-No beard - youth
-Small beard - fashion and modesty
-Long beard - wisdom