Is
it because people in the USA have such poor knowledge of geography and history
nowadays that they refer to members of the Mongoloid race of our species as
“Asians”, as if all the peoples of Asia were Mongoloid? If one is reluctant to use “Mongoloid”
(which, like “Caucasoid” and “Negroid”, is a scientific term), one could refer
to US citizens of Chinese, Korean, Indochinese, &c. ancestry as East Asian or Far Eastern; even these
words are imperfect, since, e.g., the Ainu of northern Japan are considered to
be mostly Caucasoid, but they would be satisfactory for informal speech.