Agreed, but I don't think Americans take it for granted; I think they just don't abuse it. By not abusing a good faith return policy you allow the company to provide one that is consumer friendly.
Eh, look what happened to LL Bean, they had one of the last real good faith return policies, and it was abused to hard they had to reverse lifetime warranty on existing products to two(?) years. And create a list to track individuals making the returns
I hear they'll still honor it in some obvious cases...