Of course you are correct about sushi in Japan. But the ultimate sushi for me would be made by a skilled sushi maker with brown rice. White rice in sushi is filler and detracts. I far prefer brown rice with sashimi on the side. Along with pickled ginger, soy sauce and wasabi on the side. Even some high quality vinegar. Fresh ginger sliced thinly is just as good as the pickled. I have deconstructed the sushi strategy and know it, understand it better than the Japanese
I could never figure out why, that if Japanese, Koreans etc are so smart, they are addicted to white rice
One of the reasons why Japanese use mainly white rice is because white rice lasts longer in storage than brown rice.
Another reason is that they have become accustomed to how easy it is to chew and digest. Brown rice requires more chewing power to properly digest than white rice does.
Finally, many Japanese /Asians choose white rice over brown rice because it is less expensive. White rice is far less expensive to produce and distribute because it is in greater global demand and produces higher profits because of its longer shelf life.