Embrace? Doesn't it's usage depend on the audience?
Once again, it is , or has been, considered as 'slang'. It is in the dictionary, so it is a part of our 'language'.
I believe the context of the article of this thread is that she used it improperly. Given that it is part of the 'black' culture to use a redneck white slang word instead of the proper contraction, (and that blacks seem to avoid the letter 's') I do not find it odd that she said "ain't".
Back to the original point about the guardians, just who are these people and where do we contact them?
It's not like school teachers tell students that "ain't" is not the proper contraction. Even if they did, it hasn't appeared to work very well.
If you fushizzle my dizzle.
I don't think I want to do that, it just ain't my thang.
I've figured out the identity of the (collective) guardian of English language: it's the BBC.
It lives in a castle on a hill somewhere near London. The castle has high walls, turrets, a moat and a drawbridge. Don't even think of going there without an ascot.