Most of the problems look like Lisp problems 20 years ago. Maybe Python is not the best for mobile or for games, but... so what? It's great for some things, and if it excels in those, why does it need to be perfect for everything?
For languages, number of programmers translates to: higher quality and number of libs, better tested, more work on the efficiency, compiler, more companies built around the ecosystem, more tools, more books, more tutorials, more open source projects in and with it, more bugfixes, new APIs with support for the language, new bindings etc.
It doesn't have to be "perfect for everything", but it has to be good in the kind of things that interest the most people people now. Scientific computing ain't it.
Much better to use a bad language with 100,000 programmers than a good one with 1,000, as people reluctant of JS in the past have found out.