The point is that a segfault is not an indication for memory unsafety. It is the opposite: The OS stops some unsafe access. The problem with C implementations is that it often comes to late and the segfault does not stop a prior unsafe read or write. But this is also an implementation property, you can implement C in a memory safe way as many have shown. Rust has, unfortunately, changed the narrative so that people now believe memory safety is a property of the language, when it is one of the implementation. (there are, of course, language properties that make it harder to implement C in a memory safe way without sacrificing performance and/or breaking ABI).