every time i start a project with something other than django, i end up with django, but "homebrewed".
example: you start with flask. you need auth, so you add flask-login.
you need some database access, so you add SQLAlchemy (and its flask plugin). you also need some kind of admin page, so you add flask-admin.
when you are finished, you have a flask-django framework, but not as well integrated -- with django, you get ALL of those all of those out-of-the-box, everything is well oiled and well integrated.
so, yeah, imho django is an amazing backend framework that does its job perfectly, specially when you add some really good libraries (like django-rest-framework).