As far as the origination of electronica in the early days you have to give credit to a few other big names also, not just the people who played a synth. TD played a big role because there were one of the first to use computers with there music and have large elaborate machines to creat sound.
I aslo think that Tubular Bells plays a big role by introducing complex arrangements of different sounds,
Let us not forget Jean Michel Jarre and Vangelis
Also I would say that Vangelis and Mike Oldfield are modern day composers using modern day instruments
Vangelis began composing his music at the age of five and has been credited as being todays modern mozart but that's just somebody opionion.
There alot of people who play a large role in electronica these days. I know for a fact that from my father exposing me to the the aformentioned people it helped develope my tasts into what they are today. I listen to mostly just psytrance. The way I look at it the more complicated the better