> I'm not much of a Mac user but I'm guessing the parent comment wanted readonly user install path so accidental/malicious rm -rf only affects the user data and not the installed programs?

That's one possible interpretation, but it's at odds with how most people use the `$PATH` anyways -- there's lots of local read-writable stuff on it in typical cases. And of course, even without that, persistence is trivial for an attacker with local code execution.