A major cultural component of the US is the cult of wealth. You're kind of taught/expected to put forward the veneer and appearance of economic success and wealth, even if you are neither. Fundamentally, Americans have been taught a sort of economic moralism that goes that good people become wealthy people and bad people become poor people, ergo the wealthy are good and the poor are bad. So, you want to project that you're a good person, and one way to do that is projecting the appearance of wealth. Shit drives me bananas, man.