There are other circumstances that many NBA fans neglect in the development of players. Even if you read different books by Malcolm Gladwell you start to realize success cannot be reduced to one thing (ie talent). There are plenty of talented basketball players. Some are more talented than others, but especially late the draft, teams have taken all the sure talents. That those players are ranked on draft boards shows that teams know they have talent, but their success is determined by many other mitigating factors.
For example, some guys who are taken later in the draft carry a chip on their shoulder that fuels their play. It's fair to ask whether or not they would be as successful had they been taken earlier in the draft.
Another circumstantial item that affects player development is personal matters, of which NBA fans know very little. What kind of friends/girlfriends do players have? Can they follow them to a certain draft location? Will they be a positive or negative impact? We hear of the worst examples of influence as fans, but what about an influential friend who's encouragement and responsibility helps a player eat more healthy, get to sleep on time, workout, and gain confidence?
Or what about veteran presence on the team? What about playing time? What about the player's personality and how he connects with coaches and trainers? What about the coaches' and trainers' personalities?
Player success is not a static thing. It's not set in stone like NBA 2K. Players that are drafted later and have success speak more to the quality of the franchises that select them (and their player development) than it speaks to a GM who drafts early "missing" someone.
In those terms, I'm happy with the Celtics' player development system. They could improve for sure. This is the second time they draft an overweight big who ate himself out of the league. That's frustrating.
Still I think the Celtics are above average to good at player development. And I think once we develop a firmer system and instill more foundational players, players will be able to develop better around them.