Spanish is a language I speak commonly, and in the Spanish-speaking world, particularly in Latin America, there is a great deal of -- please excuse my use of colloquial language, but it is by far the best word for the job -- butthurt over the use of the word "americano" ("American") to refer to people from the United States. The prevailing thought is that America is a continent (or a set of two continents, or one big, dual continent), and so, technically, everyone from anywhere on or about either continent is an "americano." Some people dispute this, but it is becoming politically incorrect to refer to Americans as "americanos" in Spanish.
For the curious, other terms, such as the somewhat confusing "norteamericano" (lit. North American, but meaning just "American" in common usage), or the clumsy "estadounidense" (lit. Unitedstateser") a completely made up word, are now the preferred nomenclatures.
Why is this not the case in English, or, to my knowledge, any other world languages (I am not sure about Portuguese)? Why have we not evolved a sense of "continent-ness" as Hispanophones have? Why do we think of "America" as a single country by default, and have no problem with this? Or, to ask the question a different way, why have Hispanophones developed this sensitivity toward the use of the term to describe Americans?
EDIT: Feel free to answer in Spanish!
EDIT 2: Wow, a lot of downvotes for this question... does it violate the rules in some way? Should I rephrase?
We can but blame the founding fathers for their poor choice of a national name. "Columbia" was suggested but rejected, leaving "The United States of America", which is difficult to derive a collective citizen identifier from other than "Americans".
"Norteamericanos" is almost certain to irritate Canadians, Mexicans, Nicaraguans, Guatemalans, Hondurians, Costa Ricans, Belizeans, Salvadorians, and Panamanians. It is also likely to find objection from Cubans, Jamaicans, Haitians, Dominicans, St Lucians, Vincentians, Grenadians, Bahamians, Bermudans (and probably some others I have forgotten).
So, although the citizens of the United States have taken over the name of two continents and applied it to themselves, it is really only because all other constructions are awkward. Citizens of other countries in the continents of North and South America should be glad that their founders happily gave their countries much more sensible names with more easily derived collective terms.