The quote was "corrupt file corrupts important memory" which is exactly what WUFFS is for. In Rust you can screw up badly enough to still have the bug, doing so is harder but not impossible - but in WUFFS the stupidest file format parsing you can do is merely wrong and can't corrupt anything. In WUFFS possible outcomes of incompetent morons reading an image file include: the colours in the image are wrong, the image is just a solid black or white rectangle because they didn't remember to actually render the image, bits of it are smashed up somehow, and so on. Notice how it's always about the image? WUFFS can't express programs that do other stuff.

General purpose languages are cool, but their unlimited expressiveness is exactly what you don't want for security. Why is this PNG loader able to make network connections and control my camera? You know a bad guy will find a way to force it to use those capabilities right?