No, of course not
Illiteracy is not ok with me, but cultural differences are.
I'm originally from Canada and still, after years in the US, spell some words with that pesky extra u, as in "harbour." (I've been cured of the word "colour" because all programming languages I've used demand it be spelled without the u.)
People in this area of Illinois use the word "anymore" in ways that I previously would have said are just plain wrong. It's a "regionalism." And languages change over time in any case, which is one reason why different editions of dictionaries are published. Just because something may not sound right to my ear, based on my background, does not make it wrong.