I think they need to grow up, but they won a ton of games playing good basketball. Even in the first couple of series, which they were in trouble here or there, when they moved the ball and were disciplined, everybody came through, even cancers like Butler.
I think for Westbrook and Durant, it's just about growing pains. They're both extremely talented, and frankly, Durant gets a lot of blame for not going one-on-one every possession, which really is the sign of a player that understands the team game.
Lebron had the same problem, and eventually grew up as a player.
The freethrow thing is disgusting, and that's something I actually despise from Brooks. A coach that explain losses with "we're a freethrow shooting team" isn't a good coach. But he's not McHale bad either.