What you call “polluted” is actually very common for open source
projects. It’s clear that a vendor will aim to use a more consistent
approach, simply because their internal policies typically require
Please also take into account that in Python PyPI package name !=
Python package name, i.e. a PyPI package is well able to install to
a completely different Python package on PYTHONPATH.
Your example with drop-in PyPI packages for a particular Python
package can easily be made to work, because of this.
The only benefit I see from having prefixes reserved to vendors
is to make it easier for users of those PyPI package to quickly
identify the source of the package.
But then again: they can have the same easy of use by simply looking
at the package maintainer field, so it’s only a very minor win.