Having also read Gregory Szorc's article I think he did a good job of highlighting what truly separates Rust from other languages. Any mention of Rust is bound to mention memory safety, but to me it's more than that.
Rust promotes correctness by making you handle edge cases and errors.
Rust moves a huge number of what would be runtime errors in other languages to the compile stage.
To me, those two things, although often tied very closely to memory safety, are what makes Rust truly special. It's not (just) about memory, it's about correctness.