You'd think Americans would embrace it as desirable, but accept it as mandatory, no?

After reading this again, I would think that Americans would accept it as the norm, as something normal- not necessarily desirable just something they do. Wouldn't desirable be too strong a word here?

Caitlin, I agree with you that "common" would make it a better reflection of the current society. However, time and again the author has explained that when we find in problems like this such conjunctives as "however", the problem is looking for the most opposite pair, hence the explanation picks "desirable" instead of "common". So we should only rely on the information in the problem and not on our own perception or knowledge of the world.