Not disagreeing with you here, I am wondering however if you have ever surveyed or even had casual conversation with people who self identify as "an IT person at company <X>."

In my discussions with such people[1], I have found that a preponderance of them believe that a MAC address filter is a strong protection against unauthorized equipment on their wireless network.

[1] I have had many occasions in my career where I have hired people in the IT/Ops role and during the interview process I have often probed their understanding of the plumbing of IT beyond the parameters necessary to enter on a screen in order to get something "up." My admittedly non-scientific sampling suggests that "knowing the plumbing" is not a valued skill for many of these people.