Furthermore, programming in Rust has some unique challenges (like the borrow-checker) that make traditional line-for-line or function-for-function re-writes unfavorable. The average Rust re-implementation tends to do more re-architecture than the average $FOOLANG re-implementation, which tends to make them more education.

There's also an aspect that Rust is still seen as "unproven," compared to its rather bold goals and claims. A re-implementation of something existing is a good opportunity to see how well Rust-in-practice manages to approach Rust-in-theory, and in some ways is better for that purpose than a green-field Rust project.

Personally I prefer post-mortem write-ups rather than links to an active code-base, but you take what you can get.