Its a hipster thing. It was also perhaps, for some, made popular by these guys.
Beards were even more popular in the mid-19th century than they are now.
http://www.businessinsider.com/why-beards-are-popular-2014-5
I don’t think those guys have a self esteem problem.
I frequently tell Mrs Gamecock that the only self esteem problem most young folks have today is that they have too much of the stuff.