Those aren't facts, they're anecdotes. Facts are things like "Just 18 percent of Americans report speaking a language other than English. That's far short of Europe, where 53 percent of citizens speak more than one language." [1]
Compare the language prevalence of the US, geography wise, to Europe and perhaps you'll understand the disparity. You basically have to learn multiple languages to some degree in Europe. In the US you can travel larger distances than all of Europe and speak only one language. Additionally, with English being one of the common business languages, you find that many non-English speaking countries learn English. Americans don't need to learn English (well, some might). Should they learn another language or three, of course. Is it necessary for everyday life? No. Most Americans have never left their country and likely never will. The extent of their driving can get them places that speak Spanish and French (maybe Portuguese if they REALLY drive).
I get it, Americans are fun to bash for numerous reasons, but it really annoys me when the bashing is not thought through enough to be valid.
I understand the reasons behind the disparity - and I'd say geography has little to do with it; most people in Europe learn English has a second language, not whatever language their neighbours speak. In fact, if anything we avoid learning their language, since we're at war with each other every half a century.
But understanding the reasons doesn't make invalid. If anything, it makes it more valid, since the reason we all learn English as a second language is because the Americans pushed for it, from Hollywood to the Internet. It's not like English was the natural default; my mother was still taught French. It wasn't until a few decades ago that English became the only thing we must absolutely learn.
In any case, I meant only what I wrote; that Americans don't know second languages is a fact. Whether that's cause for bashing was not part of my post.