Unsafe is part of the rust language. Theres nothing wrong with using it if you know what you’re doing. The value of unsafe is that it boxes your unsafe code - so you can direct extra care to those functions when writing, reviewing and auditing. (As opposed to C where memory corruption could happen anywhere, so you need to be careful everywhere.)
I could imagine a separate language on the programming languages shootout which is “safe rust”. It’d be interesting how the best unsafe and the best safe programs compare in speed and size.
I would say that a proper way to rephrase it would be to use idiomatic code vs unidiomatic. If you start using any high-level language in a non intended fashion (writing non idiomatic code) probably most of them would be faster.
Meanwhile: it may suggest the comparison is a work in progress, not finished or definitive.
Can data be "silly" or is it what people say about the data that is "silly"?
(The thread points out that the Nim version uses a doubly-linked list from the standard library while you'd need unsafe in Rust, and the lru crate does indeed use unsafe. So take that into account.)