a citation is most definitely not needed. it's obviously a fucking opinion. and they are under absolutely no obligation to meet your standard of proof to demonstrate anything to you. clearly citations are not a necessary condition to posting-- this comment has no citations, but yet... hey look-- it's been posted! the horror!
classic HN obnoxious "citation needed" commentary strikes again. i swear i'm just gonna keep doing this every time i see this... until i get bored and give up, i guess.
Jeez, calm down. "Citation needed" generates no more obligation than the original unsupported opinion did. Would you blow up the same way about "I disagree"?
The fact is, most opinions about what language somebody else ought to write their next library in are worth about what they cost to post.
Another is that, trendiness notwithstanding, Rust right now is best suited for a library few people will need. That may change in five or ten years. It might well not.