Your words, not mine. But gene propagation is up there, and steady wages is a sufficient if not necessary condition for that to happen.
In fact, in was the opposite.
So what are you even talking about?
Dude is saying nonsense. "Emacs users are unemployable" sounds like "Tesla drivers unregisterable" - what an imbecilic, utter bullshit that has zero sense to say. Ever.
Regardless, I don't think anyone is going to, say, avoid a specific doctor because said doctor is fond of Emacs. Same for a plumber, a baker, an electrician, a lawyer, et cetera. As a matter of fact, I have a hard time thinking of any profession where a fondness for Emacs may be considered a bad thing. Perhaps a software developer may have a harder time finding gainful employment if potential employers find out about the preference for Emacs, though that would likely only be an issue among a limited and specific set of potential employers.