13 years to get to v0.0.1 is a success? Look at how much progress Ladybird has made in a fraction of that time. Remember that these people are constantly starting rewrites of C and C++ projects (when they're not demanding others do it) in Rust "for safety" (and "oops it's MIT now"), even of ancient Unix utilities with minimal attack surfaces like the "date" command, yet when it comes to a browser rendering engine, which entails computationally-intensive, aggressively-optimized rendering of untrusted input--a massive attack surface, and the very thing for which Rust was supposedly designed--they somehow can't get the right combination of enough Rust zealots (and Adderall) to get past the finish line.
Your life might improve if you stop believing that Rust devs belong to a cult of your own imagination.
Servo was meant to be a test-bed for new architectures that might or might not be usable by Firefox. It was never meant to become Firefox' new web renderer, and it wasn't until more recently and long after the Mozilla-pocalypse that a new team took over the project with a goal of productionalizing the project as a whole. Stylo, for example, was integrated into Firefox 57 and allowed for parallel CSS style calculation, an effort that was tried unsuccessfully multiple times in C++.
Wine took a roughly same amount of time to be versioned as well, but no one calls Wine a failure.
Second, you're simply ignoring that parent poster mentioned Ladybird, a non-rust project which is advancing much more speedily than servo. And I think they have a valid point -- and while the jury is still out, it's possible that in other rust-centric efforts which have experienced foot-dragging (eg WASI), the root cause may be rust itself.
Parent poster expressed their point somewhat sarcastically, but if I (C++/python dev, I admit!) were a betting transfem, my money would be on them being right.
That said, I think the Tor project got this decision right. This is as close to an ideal use-case for rust as you can get. Also, the project is mature, which will mitigate rewrite risk. The domain is one where rust can truly shine -- and it's a critical one to get right.