Anecdotical datapoint: For a great many years I used to consider python a very slow language. Then I switched to Ruby and realized how slow a language can really be and yet still be practical for many use-cases.
I suppose it depends on how you define "that long ago" and "mainline implementations". From my point of view it's coming along to about half a decade, but I guess 1.8's remained popular in many places as recently as 2-3 years ago.
The difference does not primarily stem from raw interpreter performance but rather from the different community mindsets and resulting ecosystems.
The average code-quality in rubygems is just not very high. Consequently most libraries are completely oblivious to performance aspects.
This reaches straight into the core infrastructure (rubygems, bundler) and all major projects (Rails). Leading to the simple fact that Ruby loses out on many practical benchmarks before your script has even loaded.
Likewise the synergies of less than bright behaviors from all the gems in your average Rails project (and no least Rails itself) do indeed make the performance gap towards an average django project much larger than the mere difference in sheer interpreter performance.
That's all not meant to bash Ruby anyway. It's a trade-off me and many others are willing to make, for the convenience that ruby provides after it has finally set its fat belly into motion.
But let's not pretend these differences don't exist when everyone who has ever used both languages knows them all to well.
