units without an actual ground pin on the unit AC outlet...

There seem to be many placebos in many things in life.  In audio gear, there seems to be many units that show an outlet to connect a power cord to, but with simply the two AC pins with no ground pin.  Are these manufactures trying to just make those high-end cords useable, or at they thumbing their nose at consumer intelligence?  Or is this another thing that Nixon started? 

It hadn't, but it has now.
Through consumer products and politics, placebos/fakes have been very successful.
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There was no earth grounding on aircraft, no earth. There was/is chassis grounding.

How Are Airplanes Electrically Grounded? – Monroe Aerospace News