No I was half-listening and think it was mentioned in a loose way, and I think I'm conflating it with some other mention in a different recent podcast so that's more than a few levels of looseness.

I've just scrubbed back through - the podcast was https://syntax.fm/show/571/supper-club-rust-in-action-with-t..., which follows the pleasing practise of providing chapters (yay). It was Tim McNamara speaking from about 12'40": what he actually said was that about half of Rust learners who do drop out fall away because of the purported difficulty of the language. Very different from my faux summary so apologies for the grievous misrepresentation.

I still find Rust as hard to use as others I've spoken to do though. I'm kind of keeping at it for reasons specific to projects I have in mind, as well as a certain dense stubbornness.