Audits and fuzzing don't really make sense if it's a documented feature. Also the many eyeballs principle seems to hold given that the Debian folks found the bug.

Having said that, a lot of the core command line tools (not just the GNU coreutils) that are run against untrusted input could certainly be improved. I'd prefer the OpenBSD method though - if it can't exec then I don't need to worry about the bugs the auditor/fuzzer didn't find.