Americans are fascinated by their own love of shopping. This does not make them unique. It's just that they have more to buy than most other people on the planet. And it's also an affirmation of faith in their country.
The arc of American history almost inevitably moves toward freedom. Whether it's Lincoln and the Emancipation Proclamation the expansion of women's rights or now gay rights I think there is an almost-inevitable march toward greater civil liberties.