So there are few reasons, poor education for example. But to be frankly honest, I probably learned most of my English from watching movies (with subtitles) and using the internet while Spanish spoken movies never appeared. I only ask this question because we as Dutch can speak understand German (I can too). Kein problem. It's because of trade. And I would expect there is a lot of trade between Mexico and the United States and a lot migration and immigration as well.
Furthermore, I want to tell the real story about Mexico what I experienced there, and how much media is blowing things out of proportion, about how 'bad' the country is, full with criminals. You know what, I was in Mexico City, even in the metro, I never felt unsafe there. The city was busy, but okay, it's a 20 million people metropolitan area, so what to expect. But since Mexico also profits a lot from tourism I would have expected them to know at LEAST a bit English.
So I was also in Acapulco, at the Grand Mayan Vidante resort, and there was an older American man who wanted to exchange some money at the reception. He could not speak Spanish and with his raw voice he tried to make the receptionist understand. I thought, this resort, with rooms that costs more than 100 to 200 dollars/euro's per night, have personnel that cannot speak English? Okay, if the janitor could not do, okay, but the receptionist?
@Mickey Jon Lee - The don't need to, but having 'some' knowledge would be useful. In 2018 I went to The Philippines, also a former Spanish colony. There they spoke Tagalog and English through each other, watching tv, but many Filipino's do speak and understand English. @Adam - We do, German is obligatory in high school. @John Daniels - I guess due to lack of exposure to the language. But it's okay, my gf learns me Spanish, and me her Dutch. Having 'lessons' from a Latina is FUN. :P :-)