Having family in NY's Upper East Side (in a brownstone, no less) and living in South OC, I can't disagree with this at all.
Will those new digs in Florida be as charming? Not guaranteed, but depending on the income level, it's very possible.
Also, to be fair, there are plenty of dwellings in NYC and SoCal that completely lack charm, in addition to the other nuisances. I think if one can get past the weather, smaller restaurant scene, loss of scenery/architecture, and having to drive everywhere, quality of life could be a net increase.