The point would still be wrong. Plenty of people learn a foreign language without the ability to have much contact with native speakers. Eastern Europeans have been keen on picking up Latin American Spanish, but it’s mostly watching telenovelas or falling in love with music from there, not actually going to Latin America. People learn all kinds of foreign languages from all the way across Europe, with the only actual interaction with native speakers being maybe a holiday once a year or less. A lot of language learning plays out through exposure to media, and with the internet, Americans have no less access to media than Europeans (or, as another person here notes, East Asians).
The biggest advantage here would come from picking up Spanish. Live in a place with large Hispanic populations and you'll find plenty of media over here in Spanish in certain locations. It actually wouldn't be too difficult to immerse yourself somewhat. It's not surprising therefore that the greatest percentage of American bilingual speakers have Spanish as their other language (http://www.gallup.com/poll/1825/about-one-four-americans-can...).
I agree that media exposure can play a huge motivation. However, at least in the past, mainstream media in the United States was almost always originally in English. To use one example, in many other nations, foreign languages (English for sure at least) appear in pop radio hits constantly. In American pop music, in contrast, foreign languages rarely appear -- when present, they usually were one hit wonders, eg your "Sukiyaka", "99 Luftballoons", and "Amadeus" type songs. Obviously there are a few exceptions even "just outside" that mainstream circle (example: Rammstein) but "the norm" of US pop radio in the past was pretty much 99% English.
I do wonder if this will change a little. I am hearing more foreign language lyrics in American pop songs (mostly Spanish); some foreign media forms seem at least cult popular (anime is an example of a foreign medium with a decent sized American subculture); and as you point out, the Internet allows access to far more media forms than you could get previously.
Even in East Asia, plenty of people learn Japanese to watch anime, Chinese to enjoy Chinese classics, medieval stories, CPop, Korean for KPop, etc, etc. South Asia has a very rich intellectual tradition in dozens of languages, and a thriving (albeit scrappy) industry of film in local languages. Don't forget the time-honored trope of learning English through Hollywood movies.
America is unique in that it has created a culture that doesn't connect with the outside world at all. American sports are American, American TV shows are American, American movies come from Hollywood. It makes being multilingual in America a much rarer feat.
Depending on the school you can elect to keep studying a language in high school, and the subject weighting is quite favourable towards your final College entry rank. But most people graduate with minimal retention.
Because English is so widely spoken it is more costly (however you measure it) for an English speaker to learn enough languages to converse than it is for a non-English speaker to learn English; after all, they only have to learn one language while the English speaker will have to learn several to be able to converse with the same number of people.
In my job I talk and correspond with people who speak Castilian Spanish, Brazilian Portuguese, various South American Spanish dialects, Hindi, Gujarati, Arabic, Turkish, Norwegian, Swedish, Danish, German (including Swiss German and Austrian), French, Chinese (Mandarin and several major dialects), Vietnamese, Italian.
I speak passable Norwegian because I live in Norway but there is no chance that I could learn all the other languages, life is too short and all those colleagues speak English.
They Spanish speakers (etc.) don't learn Hindi (etc.) either for just the same reason.
If English weren't so widespread we would have to choose some other auxiliary language. For a thousand years it was Latin, then it was French, now it is English, sometime in the future it might be Mandarin Chinese.
So I don't think multilingualism is necessarily highly valued anywhere, the ability to communicate is valued and speaking the most commonly used auxiliary language gets you a lot of that.
you would really trust yourself to translate a film after picking up a language without ever speaking it with anyone?
Sure, this is completely normal. For example, coastal Albanians tend to understand Italian films, television and radio quite well just from exposure to Italian-language broadcasting, even if they never actually interact with Italians. And as I mentioned elsewhere, for a lot of people who learn to understand Spanish media, it all happens through telenovelas, not time spent with actual Latin American people.
Over the last year, I have been studying Serbian and Albanian without much interaction at all with speakers, and I am already at the point where I can enjoy many films and television programmes – sure, I might have to occasionally pause the video and rewind it or look up a word in the dictionary, but the learning and reference materials I have at my disposal are completely sufficient for that, there is no need to actually speak with anyone.