Why don't I (and most US baseball fans, I suspect) care about the World Baseball Classic? Because the US isn't really fielding a proper national team. We get the best baseball in the world from April to October and so sending the best US players to the WBC wouldn't really make a lot of sense because why would that be more important than the World Series?
A lot of folks in the US who hate sports and folks from other countries mock the idea of the MLB championship being called the "World Series". After all, it's not like we invite other countries. Moreover, the US doesn't win the WBC. But that's because if you're one of the best baseball players, you play in the MLB. The players who stay behind in Venezuela, Puerto Rico (why do they have a national team anyway?), Japan, etc. aren't nearly as good as the ones who come to play in the US. There may be exceptions; I suspect more than a few Japanese players could make in the MLB, but find the culture shift and potential for a reduced role in the US sufficiently unpleasant that they prefer to stay in Japan. On the whole, however, the World Series is the true world championship. Join me after the jump for a few stats and facts.
7 of the top 11 pitchers by WAR are from the US. Only one of them is playing in the WBC. Justin Verlander, Corey Kluber, Max Scherzer, Clayton Kershaw, Jon Lester, and Noah Syndergaard are not in San Diego playing; only Tanner Roark is on the roster. Similarly, 8 of the top 10 hitters by WAR are from the US and only one is on the US roster. Mike Trout, Mookie Betts, Kris Bryant, Josh Donaldson, Kyle Seager, Manny Machado, and Brian Dozier are not playing, only Nolan Arenado (10th) is on the team.
By contrast, foreign players that come to the US do, by and large, return to play for their national teams in the WBC. Frankly, it means quite a bit more to those countries to win here because, in an inversion of the situation in the US, the local baseball isn't nearly as prestigious.
The US team isn't a bunch of slouches, though. They went 3-0 through the first round of pool play and are playing the Dominican Republic team tonight for entry into the championship round. If the US had truly fielded its best possible team, I think it likely they would be doing even better. Of course, why bother? Most players and the MLB teams for which they play know that the more important matter is to prepare for the MLB season; the one with the championship that really counts.