Appearance-based societal norms are meant to differentiate between people who are and are not willing to join certain societies, or how much of a problem they will end up being when they do.
Copying someone's dress is saying "I agree with you".
The same principle applies to pleasantries and probably male facial hair grooming. The ladder in particular is a way of expressing mastery over the flesh.
Certain people submit to exterior grooming requirements when joining or enlisting in certain organizations. This is no different.
So, men, the rule is: you can have either a messy hair _or_ a messy beard, but never both.