I am not sure you can say we have not had consistent player development from rookie ball to the majors. And Kapler will also have nothing to do with that really. We also already spend money on nutrition and training in the minors. Who the major league manager has nothing to do with that. I am also not sure how you give Kapler credit for a guy like Turner since Turner was not a Dodger minor leaguer. Kapler was in charge of minor league development, not the majors.
Kapler is a giant unknown as a manager. The analytics background will hopefully make him more aware of things like defensive value and pitcher usage. Bullpen usage in particular is evolving really quickly and I hope he takes notice of the success of stacking two starters back to back.
As for whether he is a good hire, it is really hard to tell since there is not a track record. All of the stuff in your post is near meaningless though as the manager's job is really the major league team and optimizing it. You can take a Charlie Manuel type and still implement a nutrition program. Manuel could manage 25 personalities in the clubhouse even while he cost us a few games analytically. Hopefully Kapler can do so as well.