The electric guitar wasn't a enw things in the 1980s. I suspect the return to simplicity was a combination of two things; punk rock musicians' antipathy to the complex arrangements and elaborate production of disco, and the availability of (relatively) cheap and reliable digital synthesizers, which led to a proliferation of electronic 'one man bands.' It's easy to make all the music in a track yourself with a few electronic instruments, but if your primary skill is in the production of said music, then the rhythm, melodies, and harmony are going to be more basic.