Earlier quoted context omitted.
The original Zig code is metaphorically one big unsafe block. Even if the Rust port is made up of 3% unsafe blocks, that still means 97% of the original Zig code has been made safe (in the Rust sense).
Not every line of zig is "unsafe".
No, but when the compiler isn't enforcing anything, how do you know which ones are safe and which ones are not? If we ignore declarations etc. and only consider statement lines that read or write memory, then any such line of Zig (or C, or C++, or any other unsafe language) can be classified as a potentially unsafe — not just today, but in the future, since safety bugs can be generated upstream by giving out pointers that aren't valid or concurrency-safe.