Software modularity is good. You take many modular, reusable components and you join them together to create a bigger software that is more than the sum of its parts:
But what happens if you try to put together all sorts of modular parts, each independently designed by a smart person who believes that their way of doing things is the best in the world?
It's not exactly easy to save the world in that.
This post has been brought to you after a lot of paid work on Python, WSGI and all those sorts of mini/midi/maxi/meta/macro frameworks people built with them, that always look really, really cool until you actually start to use them for getting a serious job done.