Because the 5th-ranked team in the world got its ranking because the only decent team in its federation (besides itself) is Mexico. As hard as it is to claim victories over the football powerhouses that are Hondouras, Guatemala and Canada, I don't think the USA will win it. Heck, I don't think they'll make it out of their group.

But if it makes you happy, I'll add them. And if that was your vote for another team, let me know if you want it changing to USA.

EDIT: Whoa never mind, I just heard that USA have toppled the mighty Venezuela. Watch out, Brazil, you are sure to be next.