Pushing X versions of the same packages is the easy part (as Linus often mockingly writes, "it builds, what can go wrong")
Standing for them, and helping bugs get fixed upstream is another.
Fedora has so far refused to dilute this kind of QA work between several Python versions.
BTW in case someone felt Fedora was too conservative Python-wise, major python packages such as Plone or Zope are not in Fedora because their authors still have not made the effort to port to the python versions Fedora uses.