I agree with you on all counts. I think the only thing I can say wrt poorly/expertly written is I haven't met very many people capable of writing top-quality R

I agree with you on all counts. I think the only thing I can say wrt poorly/expertly written is I haven't met very many people capable of writing top-quality Rust (most are "I've used it for a side project or two"), whereas my professional network is filled with C experts. I expect this is due to the types of jobs I work, but the point stands: if we were to try to replace C with Rust we would likely get at most "journeyman" quality.