Ah, I'm misremembering then, in which case yeah, everyone has to select a country, if it selects the wrong country fixing it is easy.

OTOH, if it defaults to blank, people are forced to change it, if it's not blank people might not always check it's correct and errors happen, invalid cards, etc. No idea if that's a major concern-I'm going to vote for this as I think it's a good idea, but I can see there are problems with it, although some of the objections make less sense to me for above stated reasons.