Speaking my opinion and mine alone, I would not call it "hung up."
The American heritage is Christian based. Our country was founded with deep Christian beliefs which formed American law as well as allowed for the basis of morals and values (although now-a-days that does seem a bit skewed). So does it seem that American's common sense has been skewed.
It does not surprise me when you question Americans that allow faith based answers to get in the way of common sense. I would speculate that those Americans you speak of are either lacking common sense or lacking the truth in their own belief in God; or both.
As my life progresses it has become very clear to me that my faith in God is very much in line with common sense.
As far as religion... for me religion is nothing more than man made systems that attempt to interpret Gods word. Americans will often hold fast to what they know (or think they know). And I am sure this is likely the case with any human. It is difficult to remove yourself from what you have been taught and seek the truth. It is much easier to just "go with what you are told".