I don't think it's uncharitable at all. Anyone who makes a statement like "most people under 50 have never experienced a Main St" is making assumptions so large, so unexamined and so obviously incorrect that it has to be emotionally driven, especially when it's phrased along the lines of "kids today don't understand X".

If it is a legitimate observation, they must really, literally, not get out much and I would recommend driving to the nearest town with a population north of 10,000 and look around a bit to broaden their horizons. That's the generous interpretation.