Are you White? That's the differentiatng factor. If you're of South Asian or Chinese or SE Asian origin (not even nationality, origin), you face much less microagressions in other countries than you do in Japan. In general, factoring in CoL and the insular culture, Europe and other Asian countries tend to make sense. Heck, when I was backpacking out in Isan, while a number of people did go work in assembly lines or pick mushrooms in Japan on the JET visa, they preferred South Korea and Taiwan due to a (relatively) less insular culture than Japan, though Germany, the US, and Australia was the more popular option. This is reflected in diaspora demographics as well.
Anyway, I don't know why you keep talking about this kind of thing. I'm addressing ease of immigration, not how welcoming people are in particular countries. The whole thread was started because someone outright lied about immigration laws, and you keep talking about culture, which has nothing to do with the discussion.
Regardless, while I don't disagree with your facts, the original claim (not by you) was that Japan had a "hostile immigration policy that is against permanency". This is false, and sounds like a lie in fact, unless the OP just woke up from cryo-sleep after being frozen in 1985. Sure, there are real challenges to working and living in Japan if you're a native English speaker (which I am), but my whole point here is that legally, immigration here is actually very easy, contrary to the anti-Japan posts like the OP's that I frequently see on forums like this one. Immigration policy here is far, far more inviting than the US which claims to be open to immigration, yet has severe limits on visas and green cards and is legally extremely difficult and expensive to emigrate to.