its because no one cares about any other part of the americas. They're all worthless.

The Chinese call the US differently compared to the continent, "Zhou" 州 refers to the continent, "Guo" 国 to the country, same thing applies for the inhabitants of the country or the continent, you just have to add the particle "ren" 人 to refer to the people: 美国人: Americans (of the country), 美洲人:Americans (of the Continent) hence no mistake. And as far as I know the Chinese are alone 1,4 billion, and many languages copied the Chinese way to define and conceive things (the Japanese, sometimes and previously the Koreans and the Vietnamese also use the Chinese characters, and hence they certainly differentiate them exactly as the Chinese do).

Still seems to me like Chinese is not applicable to what you are saying. From what you tell me, it is like writing in English "America (country)" and "America (landweight)", except the parentheses are necessary. In truth, you can say that in China, it is said as "America", too, since 国 must goes at the end of all countries (right me if I'm wrong), 美 means America. Also, Vietnamese does not really use Chinese characters, anymore, and Japanese rarely for exonyms.

As for Spanish, as it seems you do not know it yet, it is a language spoken in several countries nowadays so this does not only include 'few Europeans', the Portuguese speakers and perhaps the Italian speakers call and differentiate them the same way.
EEUU =/= America, Estados-unidenses =/= Americanos

Well, obviously, most important thing is how it is said in English - not Spanish or French or any other tongue. Since this thread is English and most everything said on it is English. But just for fun:

English: America = USA
Chinese: N/A
Spanish: America =/ EUA
Japanese: アメリカ = アメリカ合衆国
Russian: Америка = США
German: Amerika = VSA
Portuguese: América =/ EUA
French: Amérique =/ EUA
Malay: Amerika =/ AS
Turkish: Amerika = ABD
Polish: Ameryka = SZA
Dutch: Amerika =/ VSA

https://www.youtube.com/watch?v=bpqvQ-o44RI

So you're told... we don't speak the same language, we don't wear the same clothes, we don't play the same sports, we don't share the same values, we don't have similar laws, we don't have the same problems, we don't have the same solutions to our different problems, we don't have the same politics, we don't have the same political structure, we don't have the same religious views, we don't eat the same food, we don't laugh at the same jokes, we don't care about each other and we don't have a similar ethnic make-up or cultural background or geography so apart from having languages which are intelligible to each other - same as the Dutch and Danes or the Pakistanis and Indians - what exactly do we have that's so intertwined?

I thought that this was sarcasm, and maybe it is, but I'm not sure.

*Same tongue: Yes (English). When 99.99% words are the same...it's one tongue.
*Same clothes: Yes. Everyone wears a shirt and pants, and sometimes women wear skirts.
*Same sports: Mostly. America has basketball, that's the biggest difference I can think of.
*Same values: Yes, I believe so. Tell what "values" are, though.
*Like laws: Yes, absolutely. Only difference is, in America, death punishment is rarely used.
*Like problems: Depends on person to person. There's more "rurality" in America, but New Yorkers and Londoners probably have the same problems.
*Like answers: Yes.
*Like politic build: Yes, but this's nothing to do with culture anyway.
*Same faith outlooks: Yes: Protestant Christianity and Catholic Christianity. While Britain and Ireland relatively has more atheists, pretty much the same.
*Same food: No, Britain is quite agriculturally limited contrasted to America.
*Same jokes: Yes. Blackadder is funny in America, [American high comedy] is funny in Britain.
*Care for each other: No...caring for 50,000,000 folk is ridiculous. In the broader sense, though, America is a superpower - Chinese, Indians, Japanese, they all care. Britain is also powerful and cared for by Germany, France, and other EU countries.
*Like ethnic makeup and cultural background: Absolutely. 90% folk in America have English as native tongue, and 95% or so in Britain. Both countries deeply influenced by Protestant and Catholic culture.
*Like geography: Obviously not, but this is not necessary for like culture. The Isle of Wight is obviously geographically different from the Isle of Britain, but I do not think they are not British.
*Dutch and Danish are not mutually intelligible.
*Hindi and Urdu are really stretching it for mutually intelligible - not to mention loads folk don't speak either in India or Pakistan.