I think I grok your meaning of "efficiency" now; I'm definitely not suggesting you are an intolerant person.
I would politely challenge, however, the idea that there's roughly equal virtue between Brooklyn-style embraced diversity vs Japan-style conformity. Not only does multiculturalism have a genuine moral attractiveness, which should not be dismissed, it makes for a stronger, more resilient country over the long term. Fresh ideas, fresh values, fresh labor, fresh taxpayers, fresh consumers, fresh inventors and indeed fresh culture are stengths that have been indispensable in allowing the U.S. to overcome its many deep (and often chronic) flaws and attain the level of economic and cultural success that it has. Similarly, a tendency toward xenophobia has hampered Japan's many intrinsic strengths, which have nevertheless been strong enough to set the country as an (oft misinterpreted) example of How To Win.
TLDR: Monoculture is a harmful, false optimization at the national level (though quite useful within, say, an apartment, church or startup incubator).
This reminded me of a quote from Shirow Masamune's Ghost In The Shell:
"No matter how powerful we may be fighting-wise, a system where all the parts react the same way is a system with a fatal flaw. Like individual, like organization. Overspecialization leads to death."
I would politely challenge, however, the idea that there's roughly equal virtue between Brooklyn-style embraced diversity vs Japan-style conformity. Not only does multiculturalism have a genuine moral attractiveness, which should not be dismissed, it makes for a stronger, more resilient country over the long term. Fresh ideas, fresh values, fresh labor, fresh taxpayers, fresh consumers, fresh inventors and indeed fresh culture are stengths that have been indispensable in allowing the U.S. to overcome its many deep (and often chronic) flaws and attain the level of economic and cultural success that it has. Similarly, a tendency toward xenophobia has hampered Japan's many intrinsic strengths, which have nevertheless been strong enough to set the country as an (oft misinterpreted) example of How To Win.
TLDR: Monoculture is a harmful, false optimization at the national level (though quite useful within, say, an apartment, church or startup incubator).