I see two problems here:
1. spacing
2. lack of movement within the offense
These have each been the cornerstones on our offensive success.
Every quality look that KG got, 15-17 footers off the catch, he flared off a screen away from the ball. There was 1. spacing 2. movement away from the ball.
Every time that he passed up an open look, he had another Celtic, Rondo or Pierce within 2 feet of him and his back was primarily to the basket. This creates the illusion of congestion from a player's perspective.
While at home, it's easy to see KG grab a lose ball with an opportunity to turn around and knock down a put back jumper. However, I'm sure he sees not only his defender but Lindsey Hunter or Billups, who each had several take aways around the basket in the 1st half, because our guards gravitated towards the ball.
This is a bigger problem than KG being reluctant to shoot in big spots.