Not once did Jim Nance mention that Jordan Spieth should have stayed at the University of Texas. Apparently Jim Nance didn't know that Spieth was a "one and a half and done," leaving in the middle of his second year.
The one-and-done rule is not perfect. It creates a few examples of disingenuous matriculation on the part of those who would rather have bypassed college to play in the pros. But it hasn't increased the number of such examples.
There are players who are not ready for the NBA at 18 -- but scrap the age limit and administer a "Minimum Basic Skills Test." Electricians, plumbers and teachers all have licenses. Why not NBA players?