I have yet to see any real evidence on either side of the argument. There's no precedent to show that if you coddle your best players in the regular season and limit their minutes, they will perform better in the postseason... But who knows if some teams in the past might have benefitted from more rest?
The wear and tear of the regular season really only affects postseason performance when there is an injury. While it can reasonably be suggested that more rest means injury is less likely, I'd be surprised if anyone can actually show a real-life example of this proving itself out in an actual NBA season.
Part of the problem is the small sample, since Pop is the only coach I know of that has utilized the approach to this degree. But the Spurs have been ill-prepared for the postseason the last three years, and this isn't the first season that Pop has been careful about minute distribution.
So without having any way of knowing if resting players is a good thing or not, I guess I'd prefer for my coach to have the same level of expectations of his star players that every other coach in the league has, and take my chances.
(This reflects my opinion on resting players in general over the course of the season, and not necessarily my thoughts on this particular game. I actually don't have a problem with resting Duncan but I would have liked to see Parker start the game and sit out the second half if it was a blow out.)