Although I believe he truly loves the club, there is a significant difference between loving a team and successfully managing it as a business. In the business world, failures are often talked about more than successes, and Agnelli has made some choices that have really hurt the club.
His poor decisions in managing the business have put the club's future at risk. He didn't make any plans for the future or consider the consequences of his actions. It will take some time to solve the problems that he created.
The situation with the Super League was a big problem that caused issues among European football teams and damaged the reputation of the club. It seemed like a good idea to earn more money, but the method he used was really bad. This issue will likely have a long term impact on the club.
It is not easy to think of him as a legend.