Can't blame them, even a year or two ago Ruby and RoR were much inferior to today. And wait till RoR3 hits the shelves full steam. Granted I hope ActiveRecord3 will include everything by default like DataMapper does but whatever...

Ruby is still in infancy stages, Python is quite old. Hell Python was the inspiration for Ruby.

I mean look at what is happening in the Javascript space. If Ruby and JRuby implementations get really f-ing fast, we will get some major backings. The problem is that instead of improving Ruby, Twitter decided to ditch it. Maybe they really didn't have the people Google has when it comes to language builders. Since google app engine runs python it is in direct google interest to make it fast. Once it starts running ruby, vuala! So don't worry, they'll get to it.