Pop is one of the best coaches in the NBA. A certain HOF coach. Of course, he's 1000 times more knowledgeable than us armchair coaches. When you've been as successful as he has, you tend to trust in your decisions and strategies completely. You also tend to be a bit stubborn. Because one is so close to a situation, they may be too close to see what others can from far away.
That said, despite Pops credentials, that doesn't make some of his decisions above reproach or criticism. To me, one of his flaws is that, he tends to exclusively overvalue veteran experience, even ignoring the fact that a player is clearly in decline to a point that his on-court presence becomes counter-productive. Even when there is a younger, vaiable option on the bench, Pop, like most coaches, resists and doesn't trust younger players. That's what is going on with Finley, and has for at least the past 3 seasons.
Aside from Finley, we've seen him overvalue other players like Van Exel, Horry and KT. Players who were stellar in their prime, but players who probably stayed a year too long or players the Spurs may have acquired a year or so too late.
With the roster they rolled out last year, it was obvious the Spurs were overmatched against practically every above-average team they faced. While drastic roster improvements were made over the offseason, Pop still seems reluctant to tinker with lineups that he's grown comfortable with. You cannot match quickness, strength and talent with age and experience. It doesn't hurt to shake things up. So far this season, this much we already know:
Finley as a starter or heavy-minute rotation contributor = FAILED
Bonner expeirment - FAILED
Jefferson as a lockdown defender - FAILED (he can be adequate, but not lockdown)
Pop should start experimenting more with the following:
Bogans and Hairston are clearly the best perimeter defenders on the team. They should play more.
Dice is a better defender, rebounder, and post player than Bonner. He should play more.
Ratliff is a shot-blocker, par excellance. He needs to play more.
Ian, for all his flaws, is an energetic, big that can block shots and could provide some interior presence for short bursts. He's going to make his share of mistakes, but he needs some spot minutes in certain situations, against certain teams. I'd rather live with him guarding a player like Aldridge, than watching Bonner or Finley helplessly get run over.
If Pop truly wants his team to be tougher and one that defends better, he's got to get better, tougher, defenders on the court and on the roster.
Sometimes a situation is desparate enough that a coach must throw out convention and take some chances. Though the season is young, the Spurs and Pop are already at that point this season.