It's primarily about coaching, but also about scouting.
There are always tradeoffs, in scouting potential v production (Ortiz was too much about "production", fully developed at 16 so upside was limited), in coaching finding the right balance to optimize a player's talents.
Sure you'd love a pitcher who could throw 100 MPH with 3 secondary pitches, but even then maybe you'd want him to rein it back a little to reduce stress on his arm. DeGrom isn't helping the Mets much from the IR list.
I think pitching development has to restrain young pitchers from getting obsessed with velocity, not encourage them, it's more fun to rev it up and see big numbers on the scoreboard than to focus on perfect mechanics that allow you to throw at high velocity without hurting yourself. That's where good coaching comes in, the ability to communicate and persuade, as well as scouting, picking players with the right intangibles to be coachable.
