Python has come a long way in the past ten years on packaging. Numerous Python Enhancement Proposals (PEPs) were written to improve how to install, release, and distribute Python projects.
Distutils had some flaws, which made it a little tedious to release apps. The biggest pain points were its lack of dependencies management and the way it handled compilation and binary releases. For everything related to compiling, what worked well in the nineties started to get old fashioned ten years later. No one in the core team made the library evolve for lack of interest, and because Distutils was good enough to compile Python and most projects. People who needed advanced toolchains used other tools, like SCons (http://scons.org/).
In any case, improving the toolchain was not an easy task because of the existing legacy system based on Distutils. Starting a new packaging system from scratch was quite hard, since Distutils was part of the standard library, but introducing backward...