I honestly have no clue and will only speculate. The people criticizing the "rewrite it in Rust" or "written in Rust" monikers always came across as grumpy curmudgeons to me. I never saw an actual good technical criticism.

Also they might have made the mistake of judging a very big and heterogenous community by a few zealot loudmouths (and every community has those).

Informed and objective people shouldn't judge like that but I think it reinforces a preconceived notion that they already have.

The human brain can betray us like that. If you already dislike something, practically every criticism towards it, no matter how small, makes you immediately go: "A-ha! This thing is bad! I knew it!"