What they SHOULD do.... must have a college degree to directly enter the NBA draft.
Alternatively, must play at least a year in the NBADL.
Those that do not have a college degree and go into the NBADL.... must attend college at a nearby facility re the NBADL team they are playing for... and if they get a year of credits then they may play in the NBA... subject to the team that drafted them into the NBADL
So, there would be a separate draft for those entering the NBADL.
This would get rid of all the one and doners in college basketball. But, they would still get a lot of good players as the salaries in the NBADL would not be comparable to the NBA. This should also put an end to the idea that college players should get paid.