I still believe South should be included in Django itself, but the South devs wanted to keep it as a separate app.

I remember when I first started learning Django. You follow the tutorial, write your models. Then you start playing about and want to add an extra field to a model and....oh wait, I need to either add it manually to the database or use a 3rd party app to do it.

To my mind it's part of the workflow as you build an app.