GNU's not Unix
gdb, bash and gcc are not unix tools. The FSF is quite clear on that point: GNU's not Unix. However, BSD is Unix. MacOSX incorporates a great deal of NetBSD and FreeBSD.
Most ports of GNU software are trivial-- the configure program discovers that MacOSX is a species of BSD, and compilation is relatively straightforward-- just use make (or gnumake, if you've aliased make to badmake).
I would agree that MacOSX is not free--but freedom is not what makes a OS Unix. It's what makes a OS "Not UNIX."
Why must the author log in as root immediately-- "sudo su" does much the same thing.
There is no particular guarantee that an /etc file will produce the same behaviour on a variety of Unix/GNU/other Posix OS's, so it's hard to imagine why a user would begin immediately to hack these files without discovering how netinfo.app and niutil work.