Very interesting... Most people probably look for libraries, platforms and frameworks in languages they prefer. Perhaps the decline of PHP popularity has been the biggest contributor to the demise of Drupal, in the sense of user land action.

I wonder if platforms like Django are a few years away from this. It seems that RoR is also losing lots of mindshare, it wasn't that long ago that we had a RoR article on the frontpage every other day. Such is life I guess... frameworks come and they go...