The fact they don't really need it in their life (or job). English is definitely necessary if you work service jobs in Tokyo (to deal with tourists), but not much anywhere else.
Japanese is one of a handful of languages where one can complete a postdoc entirely within the language. Many languages are not like this. e.g. in the Phillipines, STEM subjects are almost entirely taught in English, since Tagalog simply doesn't have words to describe most of the concepts. The result is something like 90% of the coursework being in English, with random Tagalog words mixed in. The concept is called "Taglish" if I recall correctly.
This is unnecessary in countries like Japan, China, South Korea, etc. If you're applying to a graduate school in Japan (or China, or Korea), expecting to receive education in English is actually the edge-case, not the expectation.
Also, at least in my company, there is an interesting trend where people are deciding learning English isn't really necessary since AI translation has gotten "good enough" for most use cases.
Spoken Tagalog has always impressed me (though I can't really say I know any) for how freely English seems to be mixed in (and well pronounced, such that you notice the difference in phonology), in varying ratios. I'm quite sure there's a deliberate code-switching to it.
> people are deciding learning English isn't really necessary since AI translation has gotten "good enough" for most use cases.
It's honestly really impressive. Although I'm told it can occasionally glitch and treat the text as a prompt instead of just translating it.
But the linked article seems to imply the opposite. I mean, working with an English PM sure sounds like the language is one of the job's core competencies.