The more I think about it, you've hit on an excellent point here. Pop, much like Duncan, has been and continues to stay in the game strictly for championships. Which explains why Pop has no use for young players. They simply cannot help him achieve his "win now" objective. It's certainly obvious that he doesn't trust them. Pop is not unlike a lot of veteran coaches, in his su ion and reluctance to develop rookies.
I simply can't see Pop hanging around after Duncan leaves and starting all over, like his buddy Jerry Sloan has done. I can't see him overseeing a rebuilding effort, and enduring the growing pains that come from losing. Why should he bother?
I believe it will take another coach, like a Quin Synder, to truly pull focus and develop a younger core of talent. Perhaps that's the best way.