Seriously though, when you really think about it, in a strange and twisted way, Vito actually was a good husband and family man.

It was his wanting to be a good husband and family man that made him make some of the decisions that he made. After the Fanucci debacle in Genco's grocery store, that caused Vito to lose his job, it was then that I believe that he decided that he would do whatever was neccessary to provide for his wife and his family. It was then that he realized in order to be a good husband to his wife and a good father to his children, he would do whatever it took not to have happen to them what happened to his mother and family.

I believe that deep down, Vito really was thinking of his wife and family when he came to the realization that Fanucci had to go.