Is it significant that Ruby on Rails seems frequently learned "framework first, then language" -- many people first learn Rails, then go to work learning Ruby. Whereas I think frameworks like Django are learned by people already familiar with Python. It's possible that folks can more easily get through the hassles and design questions posed by unit tests with a better grounding in the underlying language.
> Django are learned by people already familiar with Python
If only that were true. Like the OP I've been working with mostly legacy Django codebases the last few years and much of the same issues he raises could be applied to those projects as well.
I have no data to back that up, but it certainly seemed to happen that way.