"America for America only".

[TwilightZone]

6. The US has been referred to as America for a couple of centuries.

I get the point and agree with the sentiment, but that horse left the barn a very long time ago, died, and has been beaten ever since. It's easier to accept it as is because it's never going to change.

It has been associated with the US as long as the US has existed.

It's referred to as America around the world, probably as often as it's referred to as the US, if not more.

It's referred to as America in dictionaries, encyclopedias, and other reference materials.

There are hundreds or thousands of songs, movies, books, and other media that use the reference. America the Beautiful. American Woman. American Idiot.

It's actually kind of funny. You chastise the usage of it and say those that use it are ignorant of history, while completely ignoring the history of the term itself.