Baseball is a sport of repetition. Yes, it helps to be 6’4 with a power arm, but if you take a look at some of the best players in the game today, Altuve, Pedroia, Betts, Bradley, or if you look at the roster in Cooperstown, you will see that many of the players do not measure up to what scouts are looking for.
Learning the correct body movements and then the techniques, in the correct sequence and polishing them over and over again until it is second nature is one of the secrets to developing a player.
Teaching is art and science combined skillfully.
Attempting to teach with the traditional baseball practice model of: practice until you get it correct is outdated and not very scientific.