No idea who the hell this Coach K is but take it from me, when a team has good players it doesn't mean they have a good coach. Chelsea FC (soccer) proved that last year. A coach only becomes great if he can get the best out of his team or his coaching methods improve/help the team. You cant just judge this "Coach K" because he has the players who are "unbeatable."
If this was any other sport I'd have an easier time agreeing with you.
Hockey has a lot to do with leadership on the ice, and key players in every position.
Football has the quarterbacks.
Soccer has its superstars. You can win a soccer game with 1 superstar and a team of average players.
Basically what I'm saying is that most sports, you can get by and win games based mostly on the players you have, even at the olympics. But in basketball, especially at the olympics, it's a different story, and especially for the united states. That's a lot of young guys and a lot of BIG egos on the same team, it's the nature of being a superstar in the sport. And as they've shown basically all throughout this past decade, it's hard to put a lot of big egos like that together and succeed, and Coach K is doing it.
You have to give credit where credit is do, and the coach of the US team deserves a lot of the credit here, and it shows in the stats.