He talks about that quite a few times in the video.
The hierarchy Rich refers to[0] puts domain complexity and misconception as 10× more important than anything that's language specific. I believe this is the basis of the quote I pulled. I think this is compatible with thinking that language features are important, but domain complexity and misconception are more important issues when tackling a problem with code.
[0]: https://github.com/matthiasn/talk-transcripts/blob/master/Hi...