Aim is the problem here. Many projects are built and maintained by people who have a use case. It may well fit that use case to add one extra feature to the li

Aim is the problem here. Many projects are built and maintained by people who have a use case. It may well fit that use case to add one extra feature to the library rather than creating a new library. I suspect that many of the examples provided (such as the Django project) evolved over time. It can also often be the case that once an implementation is done it becomes obvious that it actually does something very different to what you originally set out to do.