I'll take that question. It's because Pop has always made it clear to any better-than-average player who comes here that "We already have a Big 3". I'm sure he lets them know in his own way, but when they haven't gotten the message, he has come right out and said it in exactly those words. He's made the statement to reporters, to make sure that players got the message.
No one is going to rival the Big 3, nobody is going to show up the Big 3, nobody is going to take the place of one of the Big 3. Go to the 3P line. Stand there. Wait.
People can debate whether it was the best way to handle things - he's won 4 rings his way, after all. But there is no doubt that players come here and become 3P shooting stiffs, because that's what they are expected to do. That wasn't Jefferson's game, and most of us knew that when he was signed. There was plenty of discussion about how his game wasn't really suited to Pop's coaching philosophy. It really isn't surprising that's how things turned out. I'm not happy with RJ here, but I am also convinced that his numbers would have been a lot better the last few years if he had been on another team.