While I can't find the source, I do vividly recall an account mentioning how Disney invited Goldsmith and had him ride a mockup etc. When he came down he was in tears, and they initially thought he didn't like the ride/was afraid of heights etc. But he explained he was moved to tears, because it brought up so many memories of his late father who was a hang glider and would tell him all about it, and I believe Jerry himself has hang glided as well.
Goldsmith told Disney right then and there that he must do this soundtrack. And it's that passion which most likely gave us a GOAT of a soundtrack.