I loathe Python, but I still disagree. Python is important learn, for one thing. I don't know of anyone using Java or JavaScript for statistics. For another, being unlike C is a strength . I would modify the argument to be, "Python should be taught as a foundational language, along with [insert C-like, non-GC language here] and something in the OCaml family." No one should learn CS or programming as a trade with only…
"No one should learn CS or programming as a trade with only a few languages in the same syntax family." This is a fine ideal, but I bet there are tons of professional programmers who only know a couple of languages all from the syntax family set of { C, C++, Java, JavaScript, PHP, Swift } and it's not a career problem at all.
It can be a failure of education even if it's not a career problem. The article is about what should be taught in schools.
Most programmers self-report becoming more skilled as they learn languages with different paradigms, so there's evidence that there's career benefit to knowing a diversity of languages.