The Great Wall of Y'all

We crossed into Tennessee, and while people generally don't have heavy Southern accents, there's a definite twang in the talk here. The biggest difference is, nearly everyone says y'all here, and if you don't say y'all too, they'll treat you differently. Not rudely; most people here are very polite. But they minute you walk in somewhere and say "Do you guys have..." instead of "Do y'all have...", a wall of formality goes up. Y'all deficiency signals that, at the end of the day, you neither understand nor really care about Southerners. I eventually became tempted to try throwing out a few y'alls, but on further reflection that seemed as ridiculous as going to England and trying to speak in a British accent. I'll steadfastly stick to my Californian dialect and weather whatever unnecessary formalities it may bring, though hopefully I can still get to know a few of the people here.