I do agree that with the exception of 2005, it's been "home run or nothing" since 2000.
I honestly don't know if that's an unstated overall philosophy by the organization or players get to the Sox, know the reputation of the park and just say, 'the hell with it, I'm going for the downs...'
It was my opinion that Ozzie and his staff simply couldn't teach the players any other approach. Ozzie wasn't much of a teacher in the first place...but I know Robin and his staff have worked very hard at this, even up to this spring (i.e. fewer strikeouts, more contact...putting the ball in play) Once the bell rang though it was the same old, same old. (Dayan for example has abandoned that leg / timing move already...)
Maybe the players simply are baseball stupid in that regard. That's the only thing I can think of because it's not like a ton of these guys are coming up through the system...if they were then maybe you could ask if they are being taught wrong at the lower levels.
Maybe Daver can chime in on this with some comments on how the minor league system in general teaches Sox farm hands?