I’ve heard of a case where an American man was ranting about “why can’t they speak English” despite him being in a country where it’s not even spoken (in this case: Japan), like WTF? He’s literally in another country where a different language is spoken, isn’t that already common sense? Yes, there are (some) Americans who are like this: assuming that everyone all over the world just knows English from the get go, but that’s not always the case.
Another was when an American woman wanted to pay for the bread at a French bakery using a crisp US$20 bill, but that was not accepted since France uses Euros as their main currency. I guess it stems from the fact Mexico accept that assuming that’s universal in countries where their own currency (like the Korea uses Won, UK uses the Pound, Oman uses Rials & etc). I mean, why do (some) Americans think that every country uses US Dollars?
People speaking English in tourist areas is normal, but I’ve seen Muricas complain about people speaking Spanish first or even among themselves here in Spain.
Also, no, the machine asking you USD or EUR is because your card is in USD and you can choose whether to have the bank in Spain do the conversion or let your bank do it. If you tried to give a dollar bill in that same establishment you would be informed that they don’t take dollars, or be charged an absurd conversion rate to justify his bother of having to exchange that money.