It seems...off...to tell someone to learn probably the least employable frontend framework, so they'll have "excellent mental models" for the most employable ones...

Lisp is not very employable, but it's the first language MIT taught their CS students for two decades.

I maintain that Elm is a great way to learn modern frontend development :)

> but it's the first language MIT taught their CS students

Right, which was fine because

1.) They're students at MIT. They'll be employable pretty much no matter what if they graduate

2.) They spent several years learning _other things_.

> I maintain that Elm is a great way to learn modern frontend development :)

If you then go on to learn modern frontend development after, yes. :)

This suggestion is general and applicable for all domains, Understand the basics, the foundational stuff, Don't limit your self to libraries and frameworks or even languages. They're all transferable knowledge.