Although I believe there is a modicum of a good argument here, the rest is made up of a pathetic sense of cultural superiority that is just not merited, and ignores the fact that with many differences between American English and English English, it's because the Americans have preserved elements of our common language which we have jettisoned.
The debasement of our native tongue may be aided by certain American habits, but there are more important enemies abroad. It isn't the Americans who've spent the last hundred years attacking 'bourgeois values', such as education and aspiration, denigrating the middle class and bigging up the authenticity of ignorance. It wasn't the Americans who decided that correcting children's spelling mistakes was oppressive and counter-productive to their sense of worth, it wasn't the Americans who have attempted to manipulate language for political ends, changing the meanings of words, deciding what the 'politically correct' term of the week was.
That's right: it's the fucking Fabians to blame!
Still, I'm sure Alan Partridge would endorse it.