| The South being considered an actual part of Italy is a pretty new concept and not completely accepted by either the south or the north. The north is sophisticated, cosmopolitan, industrialized, and has tons of arable farmland and just generally money running through it. Culturally it's more French / white European. The south has very little arable land, it is rocky and hilly. It does not lend itself well to large-scale agriculture. It was largely ruled in a feudal system for a very very long time, which then collapsed into the peasant families each being given land ownership of plots too small to sustain a family. It has also been a target of conquering by Greeks, Ottoman Turks, and many many many more cultures due to its critical location for shipping lanes - so it's been sort "ran over" too many times to count. The fact that the real power structure has turned over so many times has led to lots of very very localized, unofficial power structures that represent sort of local "fiefdoms" which exist outside of the modern governmental structures.
Subsequently, it has built its own mythology of being "unconquerable" or "ungovernable" and not really a part of "Italy" - where "Italy" is seen as an outside power which builds into the mythology that helps the mafioso gain and retain control. Edit: for very enjoyable (and highly regarded) novel that gets at the mafioso / Southern mythology about this, I highly recommend Black Souls. |
About the arable land, I don't know, Sicily is extremely fertile in general and there also some large plains as well like in Palermo. Sicily was extremely rich and prosper during the Normad period and for the Arabs who came before it was nothing short than a paradise.