[lllr_finger]

> they each have a profile

Absolutely true that languages are built to fulfill specific roles and have associated trade-offs. I think you answered your own question - JavaScript's strengths are being very widespread in current software development and having a minimal syntax/type system. IMO it can be a good language for MVPs/POCs and serve as a higher form of pseudocode. Perhaps the author's choice of JS as a way of reaching the widest possible audience and focusing on the concepts more than the implementation details.

A relatively recent personal example: in working through some DSL and parser combinator examples in Rust, sometimes I get too distracted with lifetimes, annotations to deal with deeply recursive functions, etc. and just search for examples in a different language that allow me to focus on the concepts I'm trying to learn.

[alex-lawrence]

Since I am asked from time to time about the technology choices for my book, I decided to write a blog post to explain my reasoning: https://www.alex-lawrence.com/posts/why-my-book-uses-nodejs-... Some of my arguments pretty much match with your statements.