[natbobc]

there was freedom I feel Ruby had that Python didn't which allowed Ruby to successfully go from 1.8 to 1.9;

* Ruby had better dependency management. Python's only recently introduced Pipenv which provides a standard approach for managing development and prod dependencies. VirtualEnv's been around for a while but didn't handle scope.

* Ruby wasn't used as extensively as Python in stuff like system libs and start-up scripts so system packages weren't constrained in the same way.

* Ruby's ecosystem was more focused around web development. Rails in particular was fairly early in adopting new versions of Ruby within about 1 year of the release of Ruby 1.9. Django on the other hand was about 5 years before it had it's first Python 3 compatible release.

* "microbenchmarks" generally got better with Ruby releases whereas Python 3 seemed to have gotten worse from what I remember. I don't think microbenchmarks are terribly useful out of the context of an actual application but many people use them as indicators.

* subjectively I think the Ruby community was more committed to unit testing which made "fearless upgrades" a little more palatable.