There's a fundamental question to ask here. Do we want to welcome Python
packages into the team, or do we want to put up barriers and require a
level of commitment before packages can be brought into the team?
Speaking for myself, I welcome anybody working on 'my' packages. As in making changes to subversion/git or even uploading packages. Sure mistakes can happen, packages might even become broken, however I think the risks of packages going unmaintained is far more damaging.
I had several packages or mine fail to get into Jessie, because of trivial release critical bugs in dependent packages, and the official maintainer ignored the bug reports. I believe this is why we have team maintainers - so anybody can work on the packages. Yes - I could have also done an immediate NMU - however not being the maintainer I wasn't aware of the release critical bug until the packages had been removed and it was too late to do anything - the release team wouldn't let one package back in despite the fact the only bug was a problem with the copyright file.
My impression is that it is a minority that get upset when people upload 'their' packages to the Debian archive without asking for permission first. I think these people tend to be active developers, so maybe these maintainers should be treated as special cases?
My understanding - correct me if I am wrong - is that nobody has ever complained about committing changes to subversion/git. Which rather puzzles me that Thomas Goirand was removed from DPMT and PAPT - I believe (am I mistaken?) this removes his ability to commit changes to subversion (which was OK), but not remove his ability to upload packages (which was not always OK).
On the other hand, if we raise barriers, we reduce the size and
influence of the team. The few packages we maintain, we can probably
maintain to a higher standard. Maybe there'd be less bickering, because
we'd be working together more (not that I think we have much).
Newcomers would be rarer (there's a commitment) but more valuable to the team. Or would we start to attract people faster because of our level of
activity?
With fewer packages in the team, we would end up with more packages being out-of-date and poorly maintained. This would lead to even more people installing packages directly using pip, and Debian packaging would become less relevant for Python developers.