Possibly because by the time the makers put out the Mac version, they were already aware of the issue, and also because the Mac has the GNU coreutils as part of

Possibly because by the time the makers put out the Mac version, they were already aware of the issue, and also because the Mac has the GNU coreutils as part of the main OS, rather than being third-party installs, so the problem was immediately obvious to the first tester who actually used it.