As to the economy of expression (which may be a red-herring) in Anglicized language, I use Dave Barry's opening reaction paraphrasing
an assent often used by Americans, "You bet your ass!" to be "I rather jolly well quite should say!" Both are equally expressive and reflect national differences.
Language is fluid and the French have railed in vain against "Franglais". Slang often cuts to the chase when formalized convention is mired in muddy verbiage. Language, a form of music, is never limited, and to force an analogy here, one kind of music doesn't preclude the value of another. Does jazz or rock vitiate classical music?
The only threat to the English or any other language is to stifle its growth. I have a vague concern that this perceived "threat" to the English language may have something to do with the agenda of the BNP.