As someone who has been living in Japan for years now, and still has a long way to go learning the language, I generally support language proficiency requirements. First, it should be noted that these are fairly common sense requirements designed to reduce fraud - requiring people applying for work visas that require Japanese proficiency to actually be able to speak Japanese. I suspect there will be more requirements in the future for things like permanent residency, but will wait for those to actually be implemented before commenting one way or another.
And second - it’s really hard to participate in society if you can’t speak the language. I think this creates resentment for both Japanese citizens and foreign residents alike.
I regret not studying sooner and harder, and a clear language requirement probably would have influenced me to try harder.
I did two years in Lausanne without speaking French and 9 years in Beijing with…maybe 2nd year proficiency in Chinese (better than most foreigners, but hardly fluent!). You can totally live in society without fluency, Switzerland being harder only because I never studied French before.
If you are doing work with a world market, you are kind of expected to speak the language of that work and not necessarily the country you are in.