These technologies are cool and good and useful but they do something different than Rust: they catch problems at runtime and mitigate the bad effects, rather than preventing them at compile time.
CHERI doesn't exist (Morello isn't available) and memory tagging is not a thing on most processors (especially not server or embedded which are where most Linux runs). Apple's MIE needs Asahi to reach M5 which won't happen for some years, and ARM servers are still quite new.
Meanwhile, Rust structurally enforces memory safety. It's simply a better option than C -- C needs closer scrutiny, more third-party static and dynamic analysis, conventions differ much more wildly, far more expertise is required, the bar to safe contribution is much higher, code review is more difficult, I could go on and on but they have reasons to prefer Rust and it's not just cargo culting.
"If we want more systems software to benefit from memory safety, we need better ways to reduce the cost and risk of migration."
What about using CHERI or Memory Tagging? Rewriting an established and mature codebase seems like the wrong approach.
This seems less like "We want to prevent memory errors." and more like "We hate C, we want Rust."
These technologies are cool and good and useful but they do something different than Rust: they catch problems at runtime and mitigate the bad effects, rather than preventing them at compile time.
CHERI doesn't exist (Morello isn't available) and memory tagging is not a thing on most processors (especially not server or embedded which are where most Linux runs). Apple's MIE needs Asahi to reach M5 which won't happen for some years, and ARM servers are still quite new.
Meanwhile, Rust structurally enforces memory safety. It's simply a better option than C -- C needs closer scrutiny, more third-party static and dynamic analysis, conventions differ much more wildly, far more expertise is required, the bar to safe contribution is much higher, code review is more difficult, I could go on and on but they have reasons to prefer Rust and it's not just cargo culting.