It's not black and white. Not everyone has the same potential obviously, but a good clubhouse environment, means you don't panic if you get a called third strike. It means you don't swing at garbage because there is a guy on 3rd base, and you want an RBI.
If you like your teammates, you play for the team. If you don't, you play for statistics. A good environment, and good character teammates bring out the best in everyone around them.
Case in point:
There was a game last year when there was a runner on third base in the 9th inning. Nobody out, and Jays were down by five.
Lawrie comes up, hits a flyball. The runner stays at third base (as he should).
Lawrie has a mini-tantrum - not because scoring that run would have increased the Jays chances of winning, but because the smart play, hurt his RBI totals, and batting average.