I think that Ralph Rinzler was very much responsible for making Doc Watson into what he became.

This idea, "Doc toured and toured for many years under this yoke - barely making a living - until he finally broke free from it and performed just exactly what he wanted to perform. If he'd stuck to his electric style, he might perhaps have been up there in Nashville with the likes of Chet Atkins, much better off financially and with less pressure on him."
is kind of dubious.

Everybody"barely makes a living" at first, no matter how good they are. Doc's claim to fame has to do with the fact that he adapted electric technique and soloing sensibilities to the acoustic guitar. His recordings with Clarence Ashley were the foundation for both his career, and for contemporary "roots music". That project was Ralph Rinzler's idea, and it changed the music world.