So don't tell people they HAVE to speak a specific language.
They don't.
Not even because you think they should.
And saying they should makes you look like an a-hole.
If it turns out most people speak Swahili, well then learn Swahili. If you walk into a business owned by a French person who speaks French, he or she is under no legal obligation to speak anything other than French, just as you the English speaker are under no obligation to speak anything other than English. Almost as many people speak Spanish in the country as people who speak English, so be prepared, especially if you continue this xenophobic instistence that everyone caught between Mexico and Canada must speak English because the majority (read: you) speak English, for the tables to be turned when English is not the majorityish's language. You'll probably be whistling a different tune then. In Spanish.
The inability to communicate because of language differences is frustrating. What saddens but does not suprise me is that as Americans our immediate--and only--answer to the problem is: Conform to our way. I know this may be a revolutionary concept, so I apologize for being so far out in left field, but maybe we could compromise? As non-English speakers learn English, maybe it wouldn't kill us to learn a little Spanish/French/Japanese/Arabic/etc.? Maybe.