> I should hope that's not how I come off.
Well... you didn't really. You seemed to be somewhat in the neighborhood, which is why I mentioned it, but not really there, so I tried to be gentle. (I hope I came across that way...)
> My meaning was more that which languages are popular is more a result of inertia than anything.
To perhaps strain a metaphor, I think it might be more like a gas cloud gravitationally collapsing. You get denser regions, which have more gravity, so they are able to attract more gas and get even denser. In the same way, a language ecosystem that has more... something... attracts more developers, which makes it a better market for third-party libraries and how-to books and consultants and tools, all of which gives it even more "something". ("Mass" is the word in the analogy; I'm not sure what the word is for language ecosystems.)
But for a project I'm going to start right now, it's perfectly rational for me to take that "mass" (or whatever) into account when choosing a language, because it means I can find programmers, and tools, and how-to guides, even if the language as a language is no better than the alternatives.
I guess that means that I'm agreeing with you about "inertia". I don't think it's just mindshare, though. It's the ability of the ecosystem to help you get your project done.
And the languages that attain that kind of "mass" are languages that were able to attract it when they didn't already have it (when they were just starting out), which is either some indication of merit, or an indication of organizational support. For organizational support, see Java (Sun publicized Java heavily, but also wrote massive libraries). For merit, consider C. (When it started out, it didn't have tons of publicity or great libraries. But it was good enough, and it was free. That was enough to start gaining a following.)