Designers of EMs and early SS placed now-mundane pinball features, like pop bumpers, ball locks/saucers, Vari-targets, and drop targets proudly front and center on machines. Contrast that with modern designs where they do their best to hide those same features behind plastics, ramps, light shows, and in the case if drop targets, optional and out of the way. I like modern games as much as anyone else, but older designs feel much simpler and purer of an experience.

Edit: Plus they're cheaper.