Kind of nervous that I'm going to re-shake that can of worms but
I don't think there is a north-south divide.
IMO, some areas have a poor rep and have become in-jokes. For example, comedians coming to Adelaide who then 'pick' on people, joking that they come from certain areas ie (and this will not surprise anyone!) Elizabeth if they want to imply they're feral or Unley if posh.
In addition to that, people like to keep prejudices going. Elizabeth, Hackham, Christies etc are all areas that get a knee-jerk reaction from people who live here. Now we all know that there is good and bad in every area and areas that might historically have a higher than average amount of dole bludgers or whatever are becoming more desirable but changing peoples attitude takes time.....and in the meantime, let's not take it too seriously!
So, not a divide, just in-jokes.