It's a little hard to be linguistically bigoted here. Even in Atlanta, loads of the billboards are in Spanish, not to mention Austin where if you aren't bilingual, you are toast.
So much Spanish, French, German, Italian, Japanese, Chinese .... hell, you name it ... has invaded the English language. Every time a new immigrant group moves in, a whole new slang starts seeping in.
Eventually, there will be some sort of global language, maybe not for several more decades, but the world is getting too small for it not to happen. I'm basically lazy, so I'd rather it be some form of English if only so that I don't have to learn another language.
Sorry I quoted all most all of your post, but I agree so completely, if I were just to state my honest opinion, it would just be a restatement anyway.
Language is NOT written in stone (OK some of it is, but that was before they had paper, let alone e-ink). But there are few people alive today that could read Beowulf in it's original transcription (I certainly couldn't). Hell, most people are confounded by Shakespearian prose. If not for the KJV of the Bible, most people wouldn't have any experience with "Thou" or "Thine".
Language will always be fluid. And ever changing.
While that presents challenges, I think it is a good thing. The bigger the palette, and the larger the canvas, the greater the ability to create new and wonderful things.
Of course, some people will just make graffiti on that large canvas, but that is a price that should be willingly shouldered.
As long as the canvas has a basis in English.
Oops! I just got bigoted.