I think that that's actually related to why Americans are accused (rightly) of being overly monolingual. It's because we have nowhere to practice any other language. Those near French Canada have something of an advantage in that respect, as well as those in Texas and Florida, due to the large Spanish-speaking population.

But in Europe, one can drive an hour and be in an area where everyone speaks a different language, so it's easier to ``practice''. Of course, that's just my provincial theory.

Edit: My point being that it's easy to practice a new computer language, as one has nearly immediate correct feedback, and, generally, one has a distinct task to perform with the language.