I still don't think that you actually disagree that the github/rubygems.org setup is an improvement over the rubyforge setup. Assuming that, I agree that the extent to which Rails had anything to do with that is debatable (and unanswerable, in fact); there was definitely an explosion of gems hosted on github that needed a new home, and I think the popularity of Rails had something to do with that explosion, but it certainly may have happened anyway.

I think lots of people find Bundler to be an improvement over straight rubygems outside of Rails projects (even if you don't), which I think fits the criteria of "an improvement driven by Rails".

I think your last sentence is the real argument you're trying to make here, and I agree with it wholeheartedly - it's incredibly frustrating that so many people seem to think Ruby is only good or useful because of Rails. I'm not one of those people!