It is not so easy, even to explain. Many books have been written about organized criminality in Italy and many have to be written yet. Consider that Cosa Nostra (the Sicilian Mafia) at the beginning of '90 had so much power that managed to start a negotiation with high functionaries of the Italian government about which laws could pass and which not (la "Trattativa Stato-Mafia", the "State-Mafia Pact"). In those regions, Italian government and organized criminality have been the same thing for a lot of time. Would you fight yourself?
Also, let me add that a radical approach had been taken by two judges, Falcone and Borsellino. They almost destroyed Cosa Nostra, at the cost of their own lives. They have been both murdered by Cosa Nostra, along with their security, in the 1992. For the curious, this is the wiki page of the State-Mafia Pact: https://en.wikipedia.org/wiki/State-Mafia_Pact
Also, let me add that a radical approach had been taken by two judges, Falcone and Borsellino. They almost destroyed Cosa Nostra, at the cost of their own lives. They have been both murdered by Cosa Nostra, along with their security, in the 1992. For the curious, this is the wiki page of the State-Mafia Pact: https://en.wikipedia.org/wiki/State-Mafia_Pact