Some of it is the language not being designed with ease of compilation in mind, unlike let’s say, to pick an extreme example, Go. Some of it is the tooling and default settings, especially around incremental compilation, linkers etc. People are working on this, but it takes time.
But unfortunately, a lot of the problem is with the ecosystem, as hinted at in the article. There seems to be no limit to the amount of code bloat and compile time complexity that people are willing to accept to win some microbenchmarks. This includes some very popular crates with lots of dependents, like Tokio.
In the C++ world, the popular “boost” library has a similar problem, and I know shops that avoid it, or large parts of it, simply because the compile times would be unbearable. I really hope that parts of the Rust community start to make similar decisions.