Want a new you?" asks a promo for TLC's midday block of makeover shows. "You're not alone!" For once, an understatement in advertising. America is the home of the new you, the uncharted land where pilgrims, convicts and Gatsbys set out to remold themselves from scratch. We ran out of uncharted land, but we didn't run out of the urge for self-reinvention. So we turned that desire inward in ever tighter circles, expressing our idealized selves through our homes, our clothes and our bodies.
Television has followed a similar pattern. A few years ago, led by the TLC hit Trading Spaces,...