While I would never argue there are companies who do not push internal data over the Internet, I am surprised you think that proves no company pushes internal data over the Internet.
i don't. my assertion is that there are significant networks that don't ever touch what we think of as the "internet" but still use IP to push datagrams around... and attempting to marginalize them as "fringe" networks that must use non-global addresses is, imho, arrogent at best.
As for counter examples, I know of a few, but confidentiality does not allow me to discuss corporate network topology on a public mailing list. Does this mean it never happens (i.e. I am lying)? If you believe that, so be it. However, the facts are still the facts, no matter what your belief is.
i know quite a few as well, the NDA still holds.
-- TTFN, patrick