> It eliminates a huge swath of potential long-term contributors who know C well and don't want to change

I don't think that swath is as huge as you think it is in 2025.

We were saying the same stuff during the Golang heydays ~8-9 years ago, and the C experts were already pretty fucking MIA.

The Linux and systemd projects are both suffering from a lack of new blood interested in writing plain old C, and the old guard is aging out. Linux is embracing Rust, which should help. I imagine systemd will do the same thing once a Rust toolchain is required to build the average distro kernel.