Great question that I don’t have a good answer to. My bit about python was more just a throwaway joke that was also supposed to indicate that my own opinions aren’t sufficient to write the linked article.

Here are some wrong answers, but with reasons for and none against:

• Assembly: really gets you to understand that you are contending with a computer chip, and that anything interesting that you want to do requires abstraction.
• C: similar to the above, but also gets you to understand some of the fundamental aspects of programming languages, mostly memory.
• Perl: if you’re willing to teach python, why not Perl? Less readable, more magic, fun language to play golf with, so tutorial exercises could be fun.

By coincidence, these are the first three languages that I encountered as a CS student with no preexisting knowledge of programming (not in this order).

Anyway, for something approaching a real suggestion: Dart/Flutter could be an interesting choice, for some of the reasons given in the article for HTML. I haven’t given this much thought so this might still be a bad answer. Also this is the language I’m using at work right now.