This would probably break too much of the ecosystem, since many top Python packages include native extensions that can only be built with a dynamic `setup.py`.
Wheels are solving that problem, but it's likely going to be many years before warning about `setup.py` is reasonable and not disruptive to the majority of legitimate users.
Wheels are solving that problem, but it's likely going to be many years before warning about `setup.py` is reasonable and not disruptive to the majority of legitimate users.