I mildly support the age limit as a bargained thing between the union and nba. I just think philosophically it's a little sad that they don't tell the truth about it. Just tell the truth of why you're doing it. Just say "Well. Realistically our scouting is so incompetent that we need the extra time to evaluate, and our vets want extra time to make money before a better athlete or an athlete projected to be better takes their job".
We see the pros and cons. So just say the truth.
You won't see the NBA saying "And oh by the way. Following our logic we also feel anyone under the age of 20 is too young to make the decision to join the military where they could possibly get their head blown off, which is realistically a far worse possible consequence than anything that could happen to them in the NBA"
I think maybe a fair compromise would be some hybrid system where you could be drafted and a team could have your rights, but then you go back to school, or maybe an independent rating agency rates the players on several levels (maturity/psych test included) and only players that they rate as top 7 are allowed to come out. That way Bron can come out, but not Leon Smith.
Kobe had great SATs and spoke Italian. Lebron was a great student. They were excellent candidates to come out. Some other guys....not so much.