I think that's a little strong. It's more like "The group controlling Javascript has mostly tried to discourage introduction of things that block".

You can, for example, do a blocking XMLHttpRequest. It's deprecated, but possible. https://jsfiddle.net/923d5sda/

The other languages don't have a builtin concurrency model. For C, Java and others event loop libraries and applications that are built on top of them can be found (nginx, netty, ...). As well as there are libraries that build on top of synchronous IO.

The eventloop was also not tied to Javascript in the older standards. Only the introduction of Promises and other stuff required the existence of an eventloop in order to define when continuations should run.

"The event loop model never blocks" is also only true as long as you (and all the libraries that you use) do not block it. There is no automatic "does not block" guarantee.

JavaScript actually always blocks. It's only external function calls that somebody took care to write in an evented style that don't block -- but anything written in pure Javascript (from for loops to text manipulation) blocks.

JS single-thread async without preemptiveness is not something to write home about...