That's because the belt system don't exist in Japan.
Here people go for dans, not belt color.
And even then, japanese judokas don't really care about dans that much.
So, if the source gives you a certificate directly, why bother jumping through hoops and playing politics, just to get that black belt?
Take a vacation, visit some famous tourist places in Japan, taste the food, train in japanese dojo, compete in Kodokan, get certified through combat, drink sake, buy souveniers for the family, fly home with memories for the rest of your life.