Oddly enough, that's also one of the advantages. small pluggable apps are the use model for django.

As opposed to what? Having to write all the code in-house yourself? Or giant, monolithic applications that are guaranteed to cross scope with one another and probably yell and scream if you try to take one of their dependencies out for ones that you prefer?

Small, independent, and interchangeable parts works. It works damn well. I've yet to see a better alternative.