Django is likely rising because Python is rising. Most people are learning Python as their first language, and Django is a logical tool for them to try to build web apps.
I seem to recall that Matz, creator of Ruby, once said (paraphrasing) that he didn't try to create a popular language, he tried to create a beautiful language.
Python's creator, on the other hand, worked at Google for a while, and like Sun, Oracle, IBM, and Microsoft before them, schools and beginners are naturally drawn to things used by the big companies.
