Good to see & hear Chowning talk about the origins!
The DX-7's lack of patch-cord 'programming' ...replaced by 32 instantly-selectable, well-conceived preset patches in RAM ... was essential in 'democratizing' synthesis. Because it wasn't easy to make new patches, it also jump-started the patch-creation business.
The 16-note polyphony also didn't hurt.
" in 1986, it was used in 40% of the number-one singles on the US Billboard Hot 100." -- Wikipedia