I think that this emphasis on explicit, built-from-scratch mathematical proofs runs counter to your previously expressed suggestion that learning via pattern matching is more efficient than learning via explicit reasoning.

My focus here was two-fold

1. Learning mathematical proof as a means of learning how to read and listen very carefully.
2. Learning the limits of rigorous reasoning by seeing how hard it is to give arguments that are actually rigorous, as opposed to just having the superficial appearance of rigor.

The second point is a part of my case for the first post that you linked.