Well, it was a lot easier to be self-taught in Newton's day... there wasn't that much to learn! You could read Euclid and you're be mostly done. Newton alone probably made learning mathematics at least three times harder during his career.

Anyway, if you're trying to make me regret choosing mathematics as one of my examples, y'all have won. I see no molecular biologists have popped up to advocate for self-taught molecular biology.