Scandals
Italian football was plagued by scandals of multiple kinds for decades. The worst of them being Calciopoli of 2006. Many clubs including Juventus and AC Milan were caught being a part of a huge match-fixing network where the teams paid the referees to influence results.
Juventus took the worst hit as they were relegated to Serie B and were stripped off of the title. Milan were given a penalty of 30 points and teams like Lazio and Fiorentina were banned from European football.
The scandal had such a huge impact on the league that since then, the clubs and the league as a whole have been on a rapid downfall in terms of revenue generated. As a result, the league finds itself in the 4th position on the UEFA Coefficient.