[gnur]

That is odd advice, the top programming languages currently used have been around for at least 19 years (python, ruby, javascript, php, java, c, objective c) and while there are new languages being developed I don't see languages like go, rust or swift pushing any of those languages out of the market.

If anything, programming languages are a long term investment and I think that learning a language that is in high demand isn't that bad of a decision, you could learn some obscure super expressive, highly functional, statically typed language, but there is large chance that you'll come in contact with javascript at one point in your career.