The Mac OS's successful commercialization of the GUI was a huge advance, and students really need to compare it to CP/M and the like to understand its importance. You don't need a detailed comparison, just test runs of the two side by side to show the difference in user experience.
Late in 1983, I walked into a computer store fully intending to buy a CP/M machine, fiddled with the interface for about a half hour, and walked out without buying one. It simply was not worth it, even as a technology writer. I'm a fast typist, the three-finger command interface was too clumsy, and nobody wanted -- or even knew how to handle -- electronic submissions.
The late Cary Lu introduced me to the Mac, in 1984, but what sold me was watching my six-year-old daughter play with one in the Boston Computer Museum. She picked up the interface in minutes for MacPaint. MacPaint and file management were similarly intuitive. I wanted a tool for writing, not to be a computer operator. I bought a Mac and got it up and running right out of the box.