But taking someone from scratch and specifically educating and training them for the job they will actually be doing also produces a capable pilot- as the thousands of examples in Europe show.
Many a year ago I got an invite into the cockpit of a QF 747 that had just departed Heathrow. In the left seat was one of QF's most experienced captains. In the right seat was a 20 something year old long blonde haired kid who looked pretty green. I thought about it for a while and realised the kid probably accepts that he is in an incredible position to be trained by one of the best kinds of teaching methods possible (in fact he could have even been the captain's son). I occasionally wonder how his career progressed and whether my judgement was proved correct.