Probably due to the small but very vocal group of pro-Rust zealots. "Rewrite it in Rust" has become a meme for a reason - and unfortunately it was more about people demanding Rust rewrites from existing C projects than doing Rust rewrites on their own.

> I don’t get why people are so militantly opposed

The author wrote about why he opposes such rewrites. You might not agree with him but you will get him… once you read the article.