> The dominant narrative behind this pushback, as far as I can tell, is nothing to do with the Rust language itself (aside perhaps from a few fringe people who see the adoption of Rust as some kind of signal of non-programming-related politics, and who are counter-signaling).

Difficult to say with certainty, because it's easy to dress "political" resistance in respectable preference for stability. (Scare quotes because it's an amalgam in which politics is just a part.) Besides, TFA is Phoronix, whose commentariat is not known for subtlety on this topic.

Replacing coreutils is risky because of the decades of refinement/stagnation (depending on your viewpoint) which will inevitably produce snags when component utilities interact in ways unforeseen by tests -- as has happened here. But without risk there's no reward. Of course, what's the reward here is subject to debate. IMO the self-evident advantage of a rewrite is that it's prima facie evidence of interest in using the language, which is significant if there's a dearth of maintainers for the originals. (The very vocal traditionalists are usually not in a hurry to contribute.)