I don't know about you, but where I come from, that's called high falutin' and condescending. I wonder if her nose was in the air when she said it? No video accompanies.urbandictionary.com gives the classic story of Ross Perot using a very similar phrase before the NAACP, including this:
Willie Clark, president of the N.A.A.C.P. branch in San Bernadino, Calif., said the overall tone of Mr. Perot's remarks and particularly his use of the phrase "your people" reflected how culturally out of touch he was with his audience.The reaction to Ann Romney's comment could well be in good measure due to the fact that it reinforces the notion that she, and they, are culturally out of touch with their audience, namely the American people.
But I'm actually left wondering about the history of this phrase. It's cleared risen in written usage, according to the Ngram below, for American English (click to embiggen).
I poked around in a bunch of the early attestations and where they were ghosts (mostly where 'you' ended a sentence and 'people' started a new one), the early ones mostly look like they're just addressing some group of people. By the 1970s, you can find some, but ever there it's hardly so clear. Anybody know when the modern meaning got established?
(Image of the t-shirt from here.)