From what to what?
Industries which have a minor league/JV and a major equivalent are few, and other industries often prefer to grow their own, starting young.
Baseball and oil come to mind, but they can more readily hire based on performance. Airlines have few performance datapoints because you basically have to screw up bad and get caught to even have a datapoint... an interviewer can't tell which candidate is so diligent that he never did an asap, vs. the asap frequent flyer who lets the SMS system cushion his slack (which is why majors fall back on entry-level checkride failures, HS GPA, etc cuz they got nothing better).
For most white-collar industries it's easier to predict success based on school performance and it's easy to fire someone who doesn't live up to expectations (or slacks off once the family obligations and burnout mounts).
Remember flow is only a carrot to staff the entry-level, they wouldn't do it unless they had to (or mainline union demanded it).