Earlier quoted context omitted.
Potentially in part because, until fairly recently (version 1.7 I believe), Django didn't have support for database schema migration built-in- https://docs.djangoproject.com/en/1.7/topics/migrations/
I see. If that's the only reason, not sure if it's a major problem with the ORM, given that you could use South instead with almost the same outcome.
https://www.kickstarter.com/projects/andrewgodwin/schema-mig...