Don't underestimate Berlusconi and realignment: Milan was close to the national average support for the Communists and Socialists during the Cold War party system.
Surely by the end it makes more sense to view PSI support in Milan as a precursor to Forza Italia?
But, yes, the Personal Appeal of Berlusconi can't be ignored in the area. Though it was really only in the elections during the early years of Berlusconi that Milan stood out - by 2006 and 2008 even it was only a few points better for the Berlusconi coalitions than average.
