Where do you find this assumption? Is it real, or is it a projection of your own mind?
Dan testing isn't a small thing. To my understanding, it's not really a done thing that you test your own students for a dan ranking. But to conflate that with ethnicity, I'd say, is nowadays more a matter of perception than reality.
I find those assumptions all over the place. In various hobbies arts and fields. One dog barks at the moon, a hundred dogs bark at the barking. It's a human condition to seek and follow a leader, but to your previous point, their are no should's. If one seeks acceptance and validation outside ones self, that's a choice, or is it. I guess it only becomes a choice when their is awareness on the part of the individual.Typically when one is observing an assumption, one is , at that instant anyway, not making or projecting it. Awareness, kind of has a way of ridding the assumption from ones mind. However the lack of awareness is quite another story.