Not sure if it's a conspiracy, but I have never seen a gardening show demonstrating wicking beds that would not lead to disaster if the instructions were followed.
In the latest Costa on Gardening Australia put in about 70mm of scoria and filled the rest with soil. About 100mm of this would stay under water and go sour unless the keeper of the gardens regularly drained them which would be a real drag.
He also said soil depth should be 350 to 500mm which is incorrect. The wicking process would not work at that depth.
I enjoy all the gardening shows, particularly Gardening Australia, and recommend it and their website to my customers. I just wish they would get the wicking system correct.