Heh. Back in the Jurassic, in a time before I gave up on Reddit, I suggested just that in some thread discussing Japan’s population and economic woes. It was amazing how quickly and thoroughly the defenders of ethnic purity and sovereign rights jumped into to scour me. “Countries have the right to control their demographics!”
I was all like “no shit, it’s absolutely their choice to dry up and blow away if they so choose,” which didn’t seem to mollify them very much.