It certainly sounds to me like the OP is claiming that most Moslem men have beards. If you know these terms from linguistics and philosophy, he’s presupposing that most Moslem men have beards rather than asserting that they do:
Anecdotal: It’s completely the same in Indonesia, India, Bangladesh, Iran, and Morocco. I have never been in a primarily Muslim country (or one with a sizeable minority like India) where full beards are the rule for Muslim men.
The closest thing I’ve seen to any heterogenous group where a clear majority of the male population sport beards are the Sikhs.
Beards come and go with fashion. They’re not in fashion in Indonesia so men don’t usually wear them.
Jesus, look at the history of beards in North America. In 1800 they were quite unusual; within a few generations they were as common as hell (look at Civil War photos) and then they went out of fashion again, and then sort of came back for awhile, and then you had goatees, and on and on.