I assume it's tongue-in-cheek; because "rewrite in Rust to improve performance" is such a meme, the headline is subtly calling attention to the fact that this is rarely good advice and certainly not the first lever an engineer should reach for upon running into a performance problem.
It's not the first lever an engineer should reach for regardless of the languages involved. Calling out Rust specifically feels like a bit of a cheap shot
And Go too! It's always fun to see posts from around 2014/2015 complaining about how every submission to Hacker News is now "I wrote X in Go", while now Go is the boring stuff and Rust is the hot new thing. I wonder what will be the next Rust though.
They are, but they also are too big, so at some point people will want to replace them with something simpler/smaller. Go has been used for this for some projects in C++ and Python.