Joanna, I think you are missing an important aspect of the US religiosity - serving as a totalitarian ideology.
In European countries that function was performed by the state and state-sponsored ideologies for a simple reason. Europe was politically fragmented into a handfuls of states fiercely competing against each other, but united by common religion that crossed the national boundaries (even after the Reformation). In that sense, religion was a Trojan horse for any totalitarian project whose success hinged on the blind allegiance to a nation-state. This may explain why Hitler denounced Christianity - because it professed an allegiance, even if residual, to anyone else than the Fuehrer.
In the United States, the opposite is true. The US is a motley of various ethnic groups united by the idea of common US citizenship. In that sense the idea of the republic is similar to that of Christianity in Europe - it is a force that transcends local allegiances and loyalties and creates a sense of common identity among various ethnic and ideological communities.
For that reason, allegiance to the nation-state cannot serve as the basis of a totalitarian movement in the US, because the essence of that movement is exclusion and suppression of certain social and ethnic groups. Espousing the United States means in essence espousing a universalist (at least in principle) constitution that gives equal rights to everyone, the Brits and the Irish, the Germans and the Jews, the Scandinavians and the Italian, the Whites and the Blacks and so on. Such universalism is fundamentally antithetical to any fascist movement that build its identity and loyalty on the bonds of common ethnic heritage.
In that situation, the role of totalitarian, fascist ideology in the US is performed by religion. Unlike in Europe, religious institutions are extremely fragmented - basically every immigrant groups brought their own religion with them that served them as the anchor of their identity. Unlike Europeans, most US-ers are members of their local church rather than a broader religious community that transcend ethnic, national or racial lines. Those local churches may form strategic alliances with the other like-minded churches, but they are just that - strategic alliances of local groups that can exclude anyone based on his/her social group membership, such as Blacks, Jews, Eastern Europeans, Asians, etc.
What many Europeans, including myself, find the most repugnant about the US religiosity is NOT a metaphysical emphasis on the otherworldliness or the preference of the spiritual over the material - traits that are almost absent from the religious life in the US. The most repugnant aspect of US religiosity, or at least its most conspicuous manifestations is its utmost clannishness and fascist mindset amidst cultural diversity within the state boundaries, the self-righteous "our clan ueber alles" approach to national politics.
Europeans are not necessarily anti-religion. Instead, religion, which in Europe was traditionally a universalist force, lost its universalist appeal to more secular social forces that includes, inter alia, socialism, democracy, and more recently -enviornmentalism. But what we see in the US religiosity is not an antiquated ideological affirmation of universal values - but the exact opposition of it - an anti-universalist fascist ideology promoting clan-based loyalty and exclusion.
The wide spread of the US-brand of religiosity attest to the profoundly fascist nature of the US society. That does not mean that the majority of US-ers are fascist - perhaps most of them are not (but neither were the Germans or the Italians) - but that fascist ideology has an appeal to a sufficiently large segment of the population to create the distinctive flavour that many Europeans find so repulsive. Europeans experienced fascism first hand and thus easily recognize it when they see it.
In sum, it is not the religiosity (meaning: metaphysics sum spirituality) that is so repulsive about the US, but the distinctively fascist flavour of the US society and politics created and augmented, inter alia, by the US religious institutions.
Wojtek