I would argue that most people wanting to learn about javascript would be searching for "jQuery tutorial" or "nodejs tutorial" or "coffeescript tutorial" and not "javascript tutorial"
Ruby and Javascript are made infinitely more popular because of projects like Rails, jQuery and node. A language like Python has no obvious framework helping drive adoption, so most information out there would be language-centric versus framework centric.
In case you want to prove that: Coffescript and node.js change nothing in the equation but jQuery has as much searches as python and javascript respectively:
Although it seems to me that the amount of tutorials on a language/framework do not have to have much in common with their popularity but with the beginner/pro-ratio. (under the assumption that mostly beginners write (for TIOBE) or read (for PYPL) tutorials)
