Closures work very well in Rust and are a core aspect of the standard library. The 'Iterator' trait adapters, for example, make very heavy use of closures, as do the combinators on 'Option' and 'Result'. Closures are also how you spawn threads. They are absolutely ubiquitous and quite natural.
In contrast, function pointers are very rarely used.
Are they equivalently nice in every way to closures in Haskell? Of course not. But I think your comment is swinging way too far in the opposite direction.
