That's true, but the coach has to be able to have faith in the younger players to give him something.
The Spurs have played Bonner, Splitter, Leonard, Green, and Blair more minutes this season than their veteran Big 3, yet they're looking great.
Pop has played those guys enough minutes that they are confident not just to play supporting roles, but to actually play feature roles at times, which really helps take the load off the bigger names.
If your point is that the Spurs organization is better at finding talent than us, I´d agree with you, and I´m sure Danny would, too. They´re the best in the league when it comes to finding diamonds in the rough. Doesn´t change the point that it´s not Doc´s fault if our rookies can´t force the coach´s hand.
The Spurs organization is better at finding talent, and Pop is better at managing minutes and getting more of his players involved and integrated into what the team is trying to do. I don't think it's as simple as that the Spurs are drafting / acquiring much better players.
Rondo, Jefferson, West, Gomes, Powe, Davis... the list of young players Doc trusted and who still have a career is just as long as the players he didn´t play and who are out of the league.
If someone thinks he has a better grasp on what these kids are able to do than Doc, who sees them many hours per week up close, he´s delusional (not that you have claimed that). Doc wants to win, and he will play the guys who he thinks can do that for him. It´s that simple.