Programming

Python allows you to focus on a single concept in isolation (building on what you've already learned, of course). JS has a bunch of other stuff mixed in. Like the DOM. Interacting with the DOM is necessary for any browser code. You can hide it with abstractions and boilerplate, but it's always going to surface in error messages. Debugging JS can be quite a bit harder than other languages.

Caveat: beginner JS is many years behind me. It may not be as bad as corporate code full of react and angular and all kinds of requirements.

If they're not in the CS field, and you don't want to teach them CS concepts that they don't need, then you have eliminated C as an option by your own criteria.

With C, they'll have to learn about compilers, build systems, memory management, and pointers at the very least.

The main reason to not including python is that students aren’t particularly in the CS field, they are learning it as their “augmented skill” (I don’t know what it’s called bad English). That’s why I don’t want to force them to learn CS concept which they might not even need.

That's an even better reason to pick Python, then.