We all know that language is mutable, that it must either evolve or wither away: there’s no language so pure as a dead one. Babylonian is untroubled by the intrusion of new slang, as it is untroubled by speakers. The word “slang” is itself illustrative: it was first recorded in 1756, I learn from the OED, which offers a wonderfully sniffy definition: “The special vocabulary used by any set of persons of a low or disreputable character.” Language thus signals not education, but character: not what you know, but who you are. And who you are, linguistically speaking, is all about class, innit.
It took an American to start purging the French out of English. After the revolution (not “war of independence”, thank you) the fledgling US sought to establish its independence culturally as well as politically. Moreover, the Enlightenment project of America’s founders meant emphasizing literacy education; and pronunciation had already altered over the previous two centuries. In 1828 Noah Webster produced the first American dictionary, seeking to establish America’s cultural distinctiveness. The much-maligned (in Britain) suffix “-ize” is not a modern outrage derived from US business speak, but dates back to Webster, who returned it to words derived from Greek verbs ending in “-izein”. He also took the French out of words ending in “-re”, and the “u” out of the suffix “-our”, another French spelling. In other words, when the British mock “American” spellings, they are usually defending the French. That’s what you call historical irony.