The RAF discovered that continually fixing things that ain't broke quite severely reduced aircraft availability, and significantly, maintenance induced defects were a major contributor.
What the RAF discovered, refined and developed over the years, we would now call "on condition" maintenance.
You quoted much of what AOPA had to say. Please send me a link to the original "Waddington Effect" paper. It seems people have hijacked/indoctrinated the term "Waddington effect" from C.H Waddingtons biological paper in a fallacy from authority attempt.
The nearest Qantas ever came to losing an aircraft in flight (and I am thinking of two serious incidents, one a DC-4, the other a B707-338C) were maintenance error defects.
Yes errors happen in maintenance and they are attributable to accidents and incidents. But it's a small percentage. I believe pilots are the largest and then ATC , weather , maintenance etc.
"Back in the day" I have taken quite a few aircraft on their first trip "out of the hangar". You expect to find defects, and are seldom disappointed. Some were really serious, ( keepers left off aileron pulleys, cable came off the pulley, as just one example, I could go on. Those of us with enough time under our belt all know that the first 10 hours "out of the shed" after a major inspection can be very interesting.
That is a personal anecdote , how does it relate to a study?
I really think you are comparing apples with oranges on the study. To which I am yet to find the original attributable source. In the book "The Ravens" it is mentioned that the Cessna Birddogs were unreliable. Until command changed from B-52 engineers to engineers who had worked on type. Could it just be that in 1941 they didn't have enough trained staff to service aircraft ??