You have to separate game play and the things the game has to allow for it to game from what the lore says. The whole reason you see way more cat boies and a few running around with Nuhn as their last name is because the game allows it. Same with all of the other races and jobs that shouldn't have so many or more than one.

In your play through the msq and the job/class quests only you are the exception. The fact that some of you don't want to see that split or accept it as a split shows how much you rely on it as a crutch for your argument for wanting it.