That's definitely an oversemplification of a complex problem, as anyone can understand. There is mafia also in the North of Italy, just a quick lookup to the news will do.

Really, Italy is a young and complex countries with regional differences that are almost ununderstandable to foreign people. There are many "mafias", more or less violent, more or less connected with the economic and political powers, it's not simple and it's not dicothomic, there is a very big grey area.