I'm pretty sure that pick-and-rolls are objectively more productive than postup plays though I haven't checked for sure.
The most important thing in the NBA for big men to be able to do is protect the rim and defend the pick-and-roll, there is almost no chance they will have competition that will push them to the point where they need good technique to defend either. PGs are taught in high school, through their teammates incompetence, that they should shoot as much as possible. I don't think most of the problems in high school basketball development are really fixable or to blame on the AAU system.
You can blame college basketball, for encouraging terrible defensive and offensive strategies, hurting players though I think.