The NFL can point to the NBA and the Kobe Bryants of the world as evidence of why they don't want to take teenagers.
That will make their case for them in a heartbeat.
Is Kobe a teenager? How about LeBron James? Any more stupid arguments?
Just what is the NFL afraid of? If it really thought that teenagers could not make it, then why would any NFL team draft one? Unless, of course, the NFL is concerned that it, instead of the NCAA, would have to develop its own talent.