Comment 4 for bug 709517

It allows people to have the binary anywhere in the PATH, not only where we say it must be. They might have it in /usr/sbin, or /urs/local/sbin.

utilities in /sbin or /usr/sbin are a bit special because some systems are actually setup to not include this in the PATH, and it is not strictly speaking incorrect; outside of utilities typically in sbin and usr/sbin, we should assume that the utility is found in the PATH, or that the utility is missing (or that users should fix the PATH before calling).