To reply to the OP: As a swede having spent a year in the US, this is a question I too have been pondering. Church attendance in Sweden is below 10% and slowly dropping even more.
What I observed in Nebraska (pretty conservative state, but not in Utah's leauge I think) was that a lot of people were paper Christians. Going to church, but not abiding to the doctrines of their faith or even considering themselves to be believers. Parents bring their children with them to church (and to be fair, you can't leave little children home alone) so they just grow up with it. It's a Walmarts kind of religion: plentiful and cheap, but not always that good a quality. As said before, going to church is an integrated part of society and divering from the norm is usually not beneficial.
That's not to say that there aren't people of faith attending church, or that they are even a minority, because that's not really something we can measure.
Oh and insults are rarely, if ever, an effective form of communication, and I think people know that. But what's percieved as insults vary from person to person. But jmizzle, I disagree that spiritual beliefs would be a core part of a person. Here, were spirituality is very rare and not focused on, our cores are more related to our values, morals and personalities. That can be connected to religion, but stands just as well on its own.