Language and carbonated soft drinks

What is it about carbonated soft drinks that makes them the subject of language differences? I don't know, but I certainly find it interesting that just as there are different names for the drinks in American English, there are different names in Latin American Spanish.
 
During my travels in Peru a few years ago, the term of choice for drinks such as Coca-Cola, 7-Up and Inca Kola was gaseosas, and that is the translation often listed first in dictionaries. Where I have been in Mexico, the term refrescos was often used, although it could apply to other drinks as well. And here in Ecuador, or at least in the seaside resort of Bahía where I am writing this message, the preferred term is colas, even for carbonated drinks of flavors that have nothing to do with cola. (The prominent diet drink here, by the way, is Coca-Cola Light, pronounced as it would be in English.)
 
The situation is reminiscent of the situation in the United States. Where I have lived nearly all my life, the preferred term is "pop." A "soda," the term used elsewhere, would be a type of ice cream fountain drink, not a drink one could get from a can. And the idea of calling a drink like 7-Up or an Orange Crush a Coke, which is done in some parts of the country, makes absolutely no sense to me. And neither does cola here, but it's the term I have come to start using.