If it were in e-Hell classics, the original phrase would be from the letter-writer, not the poster. The letters are, it appears, not heavily edited for content, so that one can see the tone of the original. There's no sense in calling out someone who is unlikely to be reading the discussion.
I can't recall anyone here using the phrase, at least not without being called to account by other posters. It's certainly a phrase that has no business in polite conversation. "Country bumpkin" is essentially the same idea, just dressed up in Sunday best, and is likewise a vulgar stereotype.