There are distributions that keep up-to-date, though, e.g., archlinux.
Serving the needs of python developers vs. sysadmins is a false dichotomy. Python developers develop on a system that they need to admin. One great thing about linux is that everything on a system can be kept up-to-date using just one software tool (a package manager). You are not going to convince me in a million years that this is a bad idea.
Now, for things that are needed in development you sometimes need different versions, in particular if you happen to have an OS that ships very old versions. For that purpose there should be some sort of tool and not a gazillion tools that are all incompatible and behave in slightly (or not so slightly) different ways. 'python -m venv' is different from 'virtualenv'? WTF?
Also, if your distribution is up-to-date (e.g., archlinux) and you are pinning to older version there is also a problem. As the article puts it 'pin their dependencies to 10 versions and 6 vulnerabilities ago'. And if you actually want to maintain your software in the future you, at some point, have to go to the new version anyway.