Every time I see a guy with long untrimmed beard, I automatically assume he is a linux sysadmin. Should I feel bad?

Well let's see.
I run Arch + I3 gaps. currently in college to "become a sys admin" and the beard is definitely growing. 😂

No

Hipster on his way to a barber?

He might be a "real UNIX" sysadmin.

@misiman, hipsters now wear mini mustache. The Stallman style is decades before the hipsters. Did you checked if they wear sandales and white socks? Would make the stereotype perfect :) But still just a stereotype, non of my Linux Sysadmin colleagues actually fits into it.

@rematix yes, because you're probably right 🤣

It's safe to presume also presume they have Gentoo installed, use Vi / Emacs and connect to slack using an IRC bridge.