We're supposed to say "United States" instead of "America" since the latter refers to more than just the U.S.
But what are we supposed to say instead of Mexican American or Asian American? AFAIK there is not an adjective in English that means "from the United States", aside from "American".
No other country in the America’s has “of America” in its name. American is naturally easier to say than “from the US” and flows directly from the name.
There’s absolutely nothing wrong with referring to yourself as American.
There’s something very wrong with trying to create a problem from it. Probably something uniquely…American.
But what are we supposed to say instead of Mexican American or Asian American? AFAIK there is not an adjective in English that means "from the United States", aside from "American".