Basketball is still a big man's game. Ultimately, OKC beat the Spurs because they have three legit big men and the Spurs, for all practical purposes, had none. The Spurs got beat in the middle. And I expect the Thunder's success in this post-season to kick off a new big man arms race.
In Game 7 of the Raptor/Heat series, they were crediting the improvement of Bismack Biyombo to him working with Patrick Ewing. The Spurs, to my knowledge, have never "developed" a big man in that way. I said early in the season that the Spurs should bring Fabbs in to work with Boban, and especially to teach him the PnR. I still think so.
I know this will piss off the people who are in love with all things Spurs. But the Spurs, under Pop, have never done a lot to "develop" players. That's sort of the flip side of their incredible W/L record during the Pop era, and all the years they've gone without re-building. There's just not a lot of room for players based on future potential. They have to be able to produce today - tomorrow at the latest.
As for stashing players, I've always hated it. The draft is a talent infusion, and teams that don't get full value from their picks suffer a slow, steady talent drain. There have been some very good players who went late in the first round, and well into the second round. The Spurs committed to a strategy of draft-and-stash, and lost any possibility of landing any of those players. All things considered, I think their overall talent pool (and trade value) would have been higher if they had focused on drafting players, rather than drafting stash-type players. One of the reasons they did that was because they brought back near-intact rosters, and wanted to bring in vets to fill the remaining spots, so they drafted guys who they knew wouldn't be available for several years, when they might have room for them. I think they would have been better off trading picks for future-year picks, or trying to bundle a few to move up a few places in the first round.
I told RC that repeatedly, until he got that damn restraining order.