The difference is that (almost) everyone has a printer, and a printer is only any good if it reproduces the image it prints exactly - and where's the fun in that? With plotters, you can do all the cool things described in the article, plus they have the advantage of being much more exotic, kind of like the LCD monitor sitting on your desk vs. the vector display used for https://en.wikipedia.org/wiki/Asteroids_(video_game)