When evaluating your player development program it is VERY important to keep everything in perspective. There is no question that we want to turn every player that we work with into an all star level talent. The reality is that it's an impossible feat to do so and that is ok.
Player Development , when done correctly has to be thought of in most if not all cases in the long term and not the short. Players take time to develop and we need to put their upside in perspective. The first thing that should happen is to evaluate every player that you are working with breaking down some important factors of their game.
Everyone wants to take glory in developing the next superstar. That is not how a good player development program works. The best development programs in the NBA aren't the ones that turn out All Stars year in and year out They are the teams that can turn undrafted/unwanted players into serviceable NBA players and crack a rotation. It is about taking the player that has lost their way and needs to be put back on track to get n the top 8/9.
Player development isn't about developing players to be in your top 3 consistently. In my opinion it is about taking your 12th best player and turn them into your 9th. Take your 15th player and turn the into your 10/11th best player. Sometimes we lost focus on the task at hand. It's always more sexy to work with the best players on your team instead of working with them players that are far down the bench. They sometimes get portrayed as truly the toys from the land of misfit toys, but they aren't. They make up about 33% of basketball and can really help themselves as well as their team by developing.
Don't worry about working with ONLY the best players, take on the challenge of working with the lesser talented players on your team. They need the most work and collectively can make a GREAT impact on your team. This is for every player, not just NBA. I like to sometimes to tell stories about the NBA, but most if not all of the content that I produce can be applied to the high school and college game as well.
Work on developing a long term Player Development Program for your team/club. Start taking the initiative for consistently hitting singles and doubles in your program. Understand that grinding out development players that start 10-15 in your rotation and consistently moving them up to 8,9,10 can have a lasting impact on your program. Our craft is about digging your feet in for the long term, not just trying to get one hit wonders.