Haraka, I was going to say may be he grew up, but on second thoughts. . .
Tartare, as Flaps said, it probably more to do with capacity to learn quickly. At NAv school in the late 80s the OC allowed more reflies and remedial training than his budget allowed; he was ex-Buccs and probably being more lenient as a result.
The problem was weaker candidates and further expense down the line at FJ OCUs before being chopped. Their argument was you had to pass a real combat exam first time.