Verified answer

Narcissistic citizens call it "America" for the same reason that regular citizens call it "America": "USA" and "U.S.er" don't roll off the tongue as easily as "America" and "American". Also, our country is big enough that we don't often encounter people of the other countries.

The USA stands for United States of America and yes the USA is a country within the continent of America and yes Bolivians, Mexicans, Canadians all have the right to call themselves Americans if they want to, America refers to the continent.

I am English but I'm also British and European, the Scottish can call themslves British and European but not English the French can call themselves European but can't call themselves British or English. In the same way I can't call myself Scottish or French.