Del Neri is not as bad as people suggests, I doubt that any manager in the whole Serie A would've got Juve into Champions league.
Sure he get's many of his subs wrong an sticks with shit players like Motta but he isn't as bad as people suggest. Juve's squad is so small and I think it's the #1 reason why Juve have been shite in the 2nd part of the season, and it's because of how shallow is the depth of the squad, and not because of average players or average management. In the first part of the season Juve were sublime, with a fresh Quag and a not fully fatigued and a very motivated Krasic who raped the defences apart, Quag got injured and Krasic obviously looks tried, same with Aquialni (who also was very good at the start) and everyone else. The squad is so small and they became so tired in the end of the season and it's the main reason Juve failed, not Del Neri, not Marotta, not Pepe (not saying they didn't contribute to the failure but they weren't the main reason imo)
And people who criticize Del Neri's subs, sometimes he get's them right, last season his subs lost Roma the league, he got two wide players in the 2nd half IIRC and it opened Roma's defence wide giving the freedom for Cassano to do his job in the middle.