Top players or not, it's something no other team did before them, and they did it right here in the US. It was historical back then and it also had an impact on how Team USA prepared their teams afterwards (especially after the second defeat in 2005). I'll have to dig up an article from back then that commented that when they got back to the hotel after the game, a couple of other teams were waiting for them in the lobby to applaud them.
I didn't say 'in the Olimpics'. Ginobili's lead Argentina
was the first national team to beat Team USA since they began fielding NBA players in the 2002 World Championship (in Indiana, where Dirk was the MVP).
They're actually the only national team to this day to defeat Team USA twice since they began fielding NBA players (the second time being in Athens).