> If a student is learning on a teaching language without much adoption, there's just not much else a student can do but use the materials that part of the course.

I think that is the biggest advantage of using a teaching language. You can give them curated, high-quality examples and make sure they not led astray by crap code they find on the internet.

And in the ChatGPT era it forces them to actually learn how to code instead of relying on AI.

The main problem is that student motivation is what drives learning success. Just because something is good for them and theoretically the best way to learn does not mean they will like this. It is difficult to sell young people long term benefits that you can only see after many years of experience.

It seems to me that the majority of students prefers "real world" languages to more elegant teaching languages. I guess it is a combination of suspected career benefits and also not wanting to be patronized with a teaching language. I wish people were more open to learning language for the fun of it but it is what it is. Teach them the languages they want to learn.