Well, obviously when the "commission" was formed in the early '30s, each family was named after it's leader (it's Don, if you will).
As far as the constant changes over the years, I believe that the media and law enforcement have had as much to do with labeling the families as the families themselves.
But that's just my opinion.
I think it's more tnan opinion--it's a fact:
The Dons and their subordinates usually referred to "our borgata," or "our family," or "our organization." They never really had names until the Valachi hearings. Then Valachi told his interrogators that "this family is headed by Vito Genovese, that family is headed by Joe Bonanno," and the names got put on top of the charts the FBI showed (see here for the Valachi charts--scroll down to the bottom):
http://www.gangrule.com/gallery/maps.htmlThe news media and most law enforcement at that time were aware that organized crime existed, but they didn't have much of an idea of how it was organized. Valachi supplied the org. charts. From then on, media used the names.
It's interesting how some names stuck and others were changed. Here I'm guessing that the media and police stuck with famous and prominent names--i.e., the Genovese Family retains that i.d. even though Don Vitone has been dead for 39 years. On the other hand, the former Profaci Family got renamed Columbo because of Joe's lunatic pubicity-hound antics.