Ruby and Python is not interchangeable, and Ruby is way more powerful than Python, that's a real reason why there is no equivalent of RoR in Python eco-system [1].

Python becomes very popular not by virtue of its tools, but by virtue of its intuitive and beginner friendly syntax. Because of this essential trait the useful tools and libraries are flourishing in the Python eco-system.

You are right that RoR is like a Ghetto and RoR is not considered as Ruby language. On this aspect, I think D has done a good job to ensure that any D based library and framework will still resemble D language. Like they said with great power comes great responsibility, and I'm afraid that Jai will follow Ruby and Lisp becoming untouchable by the mere mortals except only for a selected few domain expert programmers maintaining very niche applications.

[1]Stop Designing Languages. Write Libraries Instead:

http://lbstanza.org/purpose_of_programming_languages.html