Good for Japan for standing up for their sovereignty and their identity and not letting foreigners or critics force them to change.
Why are people so against refugees assimilating into the culture that they enter? The irony is that it kinda beats diversity in that it erodes one unique culture (the host nation) and expands influence of the nation that the refugees fled (likely a hell hole that a nation like Japan is smart enough to avoid being transformed into, can't say the same for some European countries).
They're geographically isolated and don't have a society built upon conquest/migration. There are positives and negatives to both diversity and homogeneity -- unless people are being harmed to achieve or sustain one or the other, I don't think there's really a right or wrong there.
