There's an inevitable cultural isolation and inwardness that comes from being detached from other countries and their languages. The British suffer from this defect as well., even though they're only separated from continental Europe by a thin strip of water. For me the funniest part of hearing a US citizen saying "you oughta speak English!" is that almost no US citizen actually speaks English. This is because US English is a variant of the language, a stripped-down subset evolved to enable people from very different language groups acquire just enough to execute a minimal set of necessary transactions. Hence US English has only three tenses, compared to the 13 tenses of real English (for example, US speakers say "I didn't do it yet" but speakers of real English say "I haven't done it yet"). US English has no adverbs (US speakers say "see how quick she runs" whereas real English speakers say "see how quickly she is running"). US English relies on two main verbs (do and got) whereas real English has a wealth of verbs. And US speakers typically have a daily lexicon of just over 500 words whereas even uneducated speakers of real English have a daily lexicon of around 3,700 words. There is much to be admired about US English, not least its attempts at reforming spelling, but it's not "real" English and so is unsuitable to be used as a weapon in the arsenal of low-IQ racists and bigots.