Imagine that, you give young players time, despite their weaknesses / mistakes, and they develop rapidly.
Who knew?
Like Pruitt.
Counter examples are not lacking.
But unless you give the players time, you'll never know whether they're a Pruitt or a Bradley.
So you have to do a cost-benefit analysis. You can't give up wins to give everyone an extended trial. Sometimes this means let them get familiar first and when they look ready, start trying them out.
I agree that it's a cost-benefit analysis. It just seems to me that when he makes that analysis, Doc favors going with the "finished product" veterans -- guys he trusts -- over sacrificing short-term success for the sake of developing young role players, which will take the burden off the veterans later.
Again, I point to a guy like Greg Popovich who in the past few years has staunchly refused to play his veterans big minutes, even against good opponents, and has instead given significant rotation minutes to role players (late round picks, undrafteds, castoffs, foreigners) during the regular season. This has given the Spurs the double benefit of saving their veterans and identifying and integrating a number of productive, relatively young (pre-prime) contributors.
It's very rare that we see Doc make that kind of sacrifice. Doc only seems willing to keep the main guys on the bench for long stretches if we already have a big lead, and he can't seem to resist trusting veterans over young players, especially in games against tough opponents.