I think the context is important there - as far as I'm aware he's speaking as a college coach, were you only ever have players for a few years, there is a constant stream of players coming through, and you have relatively minimal investment in what happens to the majority of those players once they leave your program.
In that space it's pretty accurate and we see the same here around age grade players through to their early 20s taking the first step to professionalism. Some of the stars can make the jump to pro, some can't and some of the guys who look like a good solid player at an amateur level end up looking like a good solid player at pro level because the application is there and they rise to the level they're playing at.
It isn't permanent though, particularly in our game where there is a path to the pros well into your 20s. You can take a guy like Kellaway who was a gun at under 20s, but struggled with the step up to the pros initially. He then goes overseas gains experience and develops as a professional and comes back a changed player.
This sort of issue is why I think something like an NRC is so important. You need to get players in a professional environment (or as close as possible) to really see who is ready and able to take the next step, beyond just on field performance.
