It'd also be a loss to the US, I think. I understand that the US team is, and has always been, not considered that great? If so, then a win by the US team implies that it's an extreme event for the US team; this will attract new fans due to the publicity and novelty of the US team winning; but then, because it was an extreme event, the US team will regress to its mean and consistently lose for the indefinite future, making all its old and new fans unhappy and more than wiping out any gains from having briefly made its old fans happy until the new fans finally attrit.