How does being in the majors help a player develop if they're not dominating the high minors?
Didn't help Featherston or Goeddel to get jumped quickly, even Franco has struggled because he is still learning how to hit. Doubt it would have hurt Velasquez or Joseph to have had a full season in AAA ball.
Now when someone is dominating like Eflin was in AAA, yes, there's not much more to learn. When it starts coming "too easy" in the minors, then a player needs to be challenged.
But if you're struggling in Lehigh, why would you develop faster in the majors when you're more likely to be overpowered and kept off balance - and where ML managers tend to have less patience with struggling players. If you can't hit AAA junk, you're be in more trouble in the Show, if your secondary pitches are a work in progress, is it easier to master them on a stage where hitters tend to jump on your mistakes?
Right now, I see nothing from Knapp, Crawford or Williams that says they're ready to start everyday in the majors.