That's synthtastic! And that's back before MIDI and digital synths. That guy was probably creating all that off various analog synths, and multi-tracked to analog tape, which requires real audio engineering skills, not just this digital point-and-click we do today.
Something interesting to me is how 80's synth sounds have made their way back....into Praise and Worship music. It's not prominent and up-front in the mix like 80's music, but a lot of the songs have it in there, behind the guitars and keys, etc. Me and another guy create synth tracks for the worship team at our church to duplicate the album stuff. I used to play them live, but actually doing live music in church is cumbersome, so we just make tracks that play behind the rest of the band.
It's all point-and-click, never worry about channel space or playing badly....just point and click and do it again. Or just play anything and then point, click and drag stuff around until it sounds the way you meant it to. Skill is nice, but optional. And if you can't create the sound you want, you can usually find something online to buy that you just download and use. Guys like this who did Miami Vice had to know what they were doing, and be very quick and efficient with it.
Oddly, I hated synth-driven music growing up. Now I like it.