I think this confuses religiosity with public displays of piety. Religiosity is a form of spirituality, metaphysics or a philosophy - a conviction that there is something greater than the self, a mystery with a meaning that cannot be fully discovered, a sense of mystic connectedness to that something greater, a belief that there is an ultimate order and logic in the seemingly disjoined and chaotic everyday life experience.
From that point of view, the infantile pablum that passes for religion in most of the US "religious" institutions is anything but religiosity. It is a self-righteous drivel that rationalizes the fundamental depravity and "sinfulness" of the "American way of life, a drivel that kills all spirituality, mystery, meaning and the greater than self order of things, and reaffirms greed, laziness, selfishness, arrogance and capitulation to external manipulations - which form the pillars of the US brand of capitalism. It is a meaningless ritual that substitutes public displays of piety for intellectual, spiritual or metaphysical experience - as shallow, meaningless, and tasteless like other products of this wretched society - fast food and pop culture.
If I were a truly religious person (which I am not, although I recognize the fact that religion can be a powerful motivating force for many great things, some beautiful, other awesome, still other terrifying) - I would be genuinely appalled to call the US society "religious." The main force that keeps this system afloat is it systematic appeal to- and cultivation of- greed, selfishness, laziness, fear and ignorance. The main product of this system is wasteful mindless consumption which the public displays of piety redefine as the ultimate virtue. If I were a religious person, I would be appalled by this degradation of religion.
I think that despite public displays to the contrary, US is probably one of the least religious societies on the face of the earth - "specialists without spirit, sensualists without heart, a nullity that has imagined that it has achieved the greatest civilization ever created" (apologies to Max Weber).
Wojtek