It seems immensely unlikely that Python is more popular than Ruby because it has a good web development ecosystem, given that the one thing everyone knows about

It seems immensely unlikely that Python is more popular than Ruby because it has a good web development ecosystem, given that the one thing everyone knows about Ruby is that it has a good web development ecosystem. (Note that this applies even if, contrary to conventional wisdom, Rails is really no good at all; and even if Django is spectacularly good. As long as "everyone knows" that Rails is a superb web development framework, Python is not going to be more popular than Ruby for having a good web development framework. For the avoidance of doubt, I have no particular view on the merits of RoR and Django; I haven't used either.)