I think this is a clever concept and useful article. However, I have to disagree with the severity of this statement:

> at best, the temptation to RiiR is unproductive (unnecessary duplication of effort)

For tiny, mature libraries, this might be true.

But a rewrite in Rust can also vastly improve maintainability. If a library is under heavy maintenance (and will continue to be), your investment in rewriting it is likely to pay dividends by saving developers -- especially ones who are new to the library -- a lot of time.