It's the suede-denim sushi police, and they've come to your house for your uncool nigiri:
It might seem like a fine point to the occasional sushi eater, but to the Japanese, it's serious business. So serious that the Ministry of Agriculture has created a kind of international sushi police who will go around certifying whether or not restaurants are serving "real" sushi or not.
It was stupid before, and it's still stupid now. To use bigger words, it reflects a failure on the part of the Japanese to understand the difference between the nation and the state. Leaving aside troubling notions of sovereignty, (you can bet that plenty folk would have their tit in a wringer if the US sent cheeseburger inspectors overseas), it is foolish for the state to arrogate the power to regulate the culture of the nation to itself. The state works through coercive power (penal, financial), or its threat, while culture tends to work itself out through taste and the market. I'd argue, however, that the kind of regulatory power the state claims with AOC labeling of one kind or another is legit, as it refers to products, rather than dishes, and there is at least a semblance of a subjective standard. Also, and I make the point in the earlier post, to presume a transnational Platonic form of sushi is to stifle the development of new indigenous forms. One might as well tell the finches to keep their beaks all the same, or send a delegation of English soccer officials to Sao Paulo to tell the kids to stop playing the jogo bonito quite so beautifully.