Yeah, the self-taught concern is really missing the target in my experience too
Given how many tertiary courses are becoming increasingly vocationally focused - and feed into jobs which are extremely narrow in focus - the self-taught aspect is probably the most consistent distinguishing factor I see in exceptional engineers.
Doesn't matter if they're self-taught from zero, or self-taught on top of some technical degree - it seems to result in more breadth and depth of experience than a degree and a lack of passion does.
That said, perhaps "self-taught" is an overloaded term?
There's self-taught in traditional "autodidact" sense of: experimentation, reverse-engineering, and hundreds of small personal projects - potentially then exposed to informal expertise via usenet & BBS discussions
Then there's self-taught in the sense of: did a vocationally oriented bootcamp in 6 months and all experimentation was related to coursework
Perhaps we need to distinguish between "self-taught" and "self-guided"?