This seems like a weird statement to make to me when defending Rust simultaneously. The whole selling point of Rust is that it's supposed to let you write provably safe code. When "unsafe" is used, what you're writing can no longer be proven as safe by the compiler. Maybe you've convinced yourself it's actually safe via some other argument, but people have been convincing themselves that their code is memory safe for decades and they're often wrong. More insidiously, relying on anything in Rust that uses "unsafe" makes it seem like the compiler is proving your own code is safe, but that is no longer true.

With that said, I don't really disagree with what I think your main point is. But seeing unsafe code in Rust is similar to seeing unsafePerformIO in Haskell libraries. Both of these are much more common than the languages' respective evangelists would have you believe, and at some point it actually does start to call into question whether the languages are successful at their basic design goals. (Spoiler: I believe that they are successful more than they are not, and even in the face of the proliferation of "unsafe" code in both languages, they're still worth using.)