Some minor nitpicks first:
1. Blogofile is a de facto abandoned project. The project's inherent bugginess is a testament to the fact that the author had more important priorities to address than the design of the site.
2. Comparing Google's App Engine with Heroku is absurd and seems like a sign that the number of data points is so small that comparisons don't make much sense in the first place.
I agree that Python sites look hideous - and have often wondered whether someone should make an alternative style sheet - but I have a feeling the Python community's problem is not that of design, but legacy. As bland as Django's and Python's documentation looks, Pythonistas have come to learn where things are and how they work.
I don't know if migrating the websites of Django and Python to something new would be a good idea, especially when it comes to preserving links for directing to dead ends.
I'd rather that someone did a CSS userstyle than to see the sites get redesigned, because I think it would break more than it improves. If the CSS and HTML could be improved without any changes to URLs, then that would be even better, of course. We can't pretend the changes aren't retroactive.
Maybe someone could do a fork of the sites and apply the changes they want?
As someone said, maybe the Python people just decided to spend their time writing good documentation instead of creating a good-looking front-end? There are only so many people and resources to go around, especially in one-man projects like Blogofile. As chance would have it, I actually use Blogofile over all the alternatives, meagre design or not. Maybe I share sensibilities with the Blogofile and Python guys that don't translate to good-looking websites?