I'm in full-agreement that it's a good thing to have a basic understanding of how stuff works, but I'm not sure how enforcing vim over VSCode or Sublime or [insert your favorite editor] necessarily teaches that. It teaches adherence to vim.
I'm of the opinion that programming tools are very personal -- that's why there are so many debates and that's why we'll never have universal agreement. I know my way around the command line and I'll suffer through vim if I have to (it's fine. It's just not my editor of choice), but if I don't have my dotfiles or configurations, I'm not going to be very productive either.
I'm fine with saying, "don't use an IDE in my class, use a text editor" -- but I find it draconian and ridiculous to insist upon a specific text editor.
My preferred Unix editor is the vi family. I wonder whether emacs people are less sympathetic.