Ok, maybe that's an over simplification… but it's a big part of the problem.
Look around the NBA… you'll see guys who horrible shooting form splashing J's from everywhere. Why? They figured something out, they stuck to it, and they take their shots like it's going in every time. They're relaxed. They're fluid… even if it's ugly.
Look at Rashard Lewis. He's got an ugly looking shot. It's a terrible release. But if you leave him alone he'll murder you.
So yeah… Rajon Rondo needs to figure out some things about his elbow and how the ball sits in his hand. But more than anything… Rondo needs to take a few games early in the season, and just react to the defense when it backs off by shooting with some confidence.