Sure, he was the leader on the court, or as Pop said it their best player on the floor. But, it's off the floor that they wanted him to be someone that brings the team together and be their emotional leader, like Timmy was. But in reality it was Pop that was doing everything he could to keep Tim happy. He did not do that for Kawhi, or if he did, he failed miserably.
At the end of the day, I believe it was his health concerns and lack of leadership that made Kawhi too much of a risk for the franchize to invest the super max on him, that's what I feel happend.