Vincent was a wannabee--a nobody who tried to cash in on his bloodline to get ahead because he couldn't on his own. So, it was in his interest to glamorize his never-seen father, and to be worshipful around his uncle (notice how he calls him "Mr. Corleone" at first when Connie brings him to Michael). Sure, Vincent heard a million stories about his father, and probably some of them touched on the negative points that dt raised in his post. But, to Vincent, his father had to be "the prince of the city."