That's disingenuous. Python 3 was released around 2008, rails popularity was still rising. The community refused to upgrade for at least 10y, and several prominent libraries took as much to provide first grade python 3 support.
Ruby 1.8 to 1.9 migration was by contrast way milder. It took 6 or 7 patch releases and around five years to release 1.9.3, the first from the 1.9 series people actually considered stable, but after that the community migrated because it was *significantly* faster than 1.8 . Python 3 on the other hand was slower overall than python 3 at least until 3.6. The fact that the community stuck with python through it all does say a lot about human psychology and sunken cost syndrome.
Python 2-to-3 was mainly worse than Ruby 1.8 to 1.9 because Python had already won, and had a much bigger and more diverse ecosystem.