You got me thinking there. This January it's 25 years since I started following Juve. In these 25 years I can think of only three players who were sold from Juventus when they were young - without being given a proper chance - and then made a big name for themselves elsewhere: Vieri, Henry, and Immobile. Vieri was an economical decision by Moggi; Henry said recently that he asked to leave due to disagreements with Moggi; Both Vieri and Henry were replaced by players their age - Pippo Inzaghi and David Trezeguet. Immobile is in this list because he's 16 goals away from reaching serie A's all time top 10 goal-scorers list, and depending on his longevity, he might even attack the first place. Otherwise, I don't think many regret getting rid of him some 12 years ago.
The others who were here as u23 youngsters and weren't given a chance, but still managed to make some name for themselves elsewhere are: Tommaso Rocchi, Juan Pablo Sorin, Simone Perrotta, Abdoulay Konko, Domenico Criscito, Kingsley Coman, and maybe Merih Demiral. Not much to cry about there.
Perhaps we will/should regret not giving a chance to players we owned or had the right to buy, like Berardi or Romero, but that's it. I'm talking 25 years.
It's more logical and correct to be critical of our inability to regularly spot and buy talents, than to criticize our directors for not giving a chance to the young top talents we had.