I always thought the reasons for not developing pitchers was multi-faceted, and I think few would disagree.
1.) Drafting more hitters than pitchers.
2.) The player development personnel on the pitching side failing young players.
3.) Luck...yes I think it's partially luck. Because at the end of the day, no one can predict or mold how a human being is going to develop with precise precision even if you do everything right.
The thing is, if it's #1 and #2 more, it's going to take a long time to see the results. Think about it, if you put into place the best pitcher development staff, and the best amateur talent scouts for pitchers alive it would not result in instantaneous results. It would take years to see the fruit of that labor.
What we are seeing now is encouraging, but I'm not ready to declare victory yet. How things develop over the next few years will tell us if it's more 1&2 or if this recent trend is more #3.
You'd think if it's more 1 and 2 they'd have a pretty good ideal internally, and maybe shift towards spending little bit more draft capital on pitchers. Which to be fair, in terms of numbers they do enough, they're just taking pitchers later in the draft.