Let's just call a spade a spade, because I am sure a lot of people on here are thinking the same thing:
Forget about nationalities. Other than the occasional fluke, in the WJC tournament format, a team comprised predominantly of NTDP/NCAA players will rarely if ever outperform a team comprised predominantly of CHL players.
The style of play, the shortness and intensity of the tournament - I think they all favour players who developed their games in the CHL. "The success of the NTDP is not gauged on wins and losses, but on the development of skills and acquiring experience", according to their website. That's very sweet, but show me someone who isn't concerned with winning, and I'll show you a loser.
These players then go on to the NCAA, where they never have to grind out a 4 out of 7 playoff series; they play two games over a weekend and wait a week to play again; they see more hitting, smothering defense and in-your-face hockey in a single game against Canada than they do in four years worth of Beanpot Tournaments.
Sorry if I am offending the pro-NCAA crowd, but if anyone can think of a better reason for the USA's annual World Junior pooch screwing, I'm all ears.