Now, a computer lab where kids get a blank command-line on a Unix system, and have free reign to do whatever they want in their home directory (explore, program, ..., etc), THAT would be incredibly useful educational tool, so, of course, schools would never consider doing something as awful as that...

That describes almost perfectly my high school programming department. We all sat at green screen serial terminals attached to the large "computer" in the back corner. I didn't know it back then, but I'm sure glad they had the insight to teach us the basics without the distraction of the GUI (which did exist; they chose to use the older classics.)

Plus, I'd never have ingrained all the vi commands¹ into my brain if I hadn't taken that class.

¹What's that joke about generating a pseudorandom character sequence by asking a user unfamiliar with vi to exit the program?