Cannavaro has been utter rubbish at Madrid this season, so he could be on his last legs anyway.
You keep saying how you find it ridiculous people would rather have Tacchinardi than someone such as Emerson coming back to Juventus. Personally, I find this logical as Tacchinardi has given far more to Juventus than Emerson Ferriera. Loyalty in professional football is hard to find nowadays, and as supporters of this club we love to see such loyalty to Juventus as we are loyal to the club as well. Afterall, if we attend matches, buy Juventus merchandise etc we are helping to pay player wages, so when we see someone such as Pessotto who gave his all to Juventus and never wanted to leave, of course we will extend our hand to him before some random player who might have played here for a couple seasons.
Some fans only care about winning... others care about winning as well, but also about tradition and, as you have stated, the whole enjoyment of watching the game as a supporter. Hand in hand with this enjoyment, at least to me, comes this mutual give and take between supporters and players who both want what is best for Juventus. So while some fans are loyal to Juventus and give much of their time and money to the club, they also expect sort of the same from the players, and that is why we prefer players such as Pessotto, Tacchinardi and Scirea etc instead of those who nonchalantly come and go. Without loyalty in football the sport would have died long ago as there certainly was not an endless amounts of cash flowing into the sport like there is today.