Which is of course a fair point. A language by itself is probably not even in the top 3 considerations when choosing new tech. Stuff like runtime, ecosystem and the amount of available developers would probably be more important in most cases.
Totally depends on a domain. In serious mission critical software you wont use libraries, but will use the language.
Because C++ and C are significantly better than Nim and Crystal.
There are also Ada and Spark and aerospace and very critical stuff.
> just don't find developers who know them easily
We don't look for OCaml/Ada developers, we hire programmers, and they program OCaml and Ada. It's not a big deal for a good programmer to learn a language, especially while programming side by side with seasoned programmers.
In my 6 years with Python, the only dissatisfaction with the language I felt was from parallel programming. I switched to Python from C, and at the time, I missed C transparency and control over the machine, but that was compensated by the Python conciseness and convenience. Then I had to dig into C++ and I didn't like it at all. Then I played with CUDA and OpenMP, and Cilk+, but I wished all that would be natively available in a single, universal language. Then I started using Theano, then Tensorflow, and now I'm using Pytorch, and am more or less happy with it. It suits my needs well. If something else emerges with a clear advantage, I'll switch to it, but I'm not seeing it yet.