First off, I'm rooting for the USA to take the whole thing.
I think that if the lineup was Jason Kidd, Kobe Bryant, Tracy McGrady, Kevin Garnett, Shaq instead of the lineup we have now, then there'd be nobody "rooting" against the USA. If the current team could actually hit a 20 foot jump shot, then maybe just maybe people would cheer for them. Not everyone is a fan of the 1 on 1, playground style of basketball the NBA plays. Not having the best team we could have, and the type of basketball the team was playing up until the last 2 games, there's the obvious reasons why people would want to see the USA lose.