It's a completely different way of thinking about your data, so there is no question why they don't converge. Django's ORM has a more relational (read traditional) approach, and SQLA tries to have you forget about tables at all. While it is still more powerful Django ORM is catching up with each release.
In fact, with aggregations released in 1.1 you will be able to compose 'group by' queries without resorting to internal query object modification, and there will be very few queries that could not be expressed conveniently in Django ORM.
In fact, with aggregations released in 1.1 you will be able to compose 'group by' queries without resorting to internal query object modification, and there will be very few queries that could not be expressed conveniently in Django ORM.