My first thought on reading this was the guess that, while the questions about Javascript are about fewer topics, the questions about Python are more widespread

My first thought on reading this was the guess that, while the questions about Javascript are about fewer topics, the questions about Python are more widespread (because it gets used for more different kinds of things). In other words, if you looked at the volume of questions _read_, you might still see a substantial lead for JS, but it's even more likely that your question has already been asked (and answered) on SO, thus fewer new questions than for python. Just a guess, of course.