Looking thru that catalog, made me wonder the same thing back in the early 2000s when GM was sending trays and trays of terminal pins to dealerships. Why on earth do we need a gazillion different terminals? I guess the short answer is...That's Big Business for you! But how much easier it would be if it was standardized to 50 different terminals and mating halfs!
I'm all for not crossing the streams! But having different connector bodies that prevent cross mating might be an easier solution, and aren't as breakage prone as the pins are. Unless its an older Ford, all you had to do was look at a connector the wrong way and it broke lol!