This question has been tossed about, but was answered by AA in 1981 in the intro to The Negative, the second of his Photo Basics books.

“I eagerly await new concepts and processes. I believe that the electronic image will be the next major advance. Such systems will have their own inherent and inescapable structural characteristics, and the artist and functional practitioner will again strive to comprehend and control them.”

I was talking to Annie Leibovitz about this yesterday, she mentioned what a big learning curve there was to digital and how she missed film. I agreed and said that I was re-reading Ansels’ books from the viewpoint of digital (since when I first read them in the 60s.) It is the hallmark of these professionals to “continually strive to comprehend and control” their medium, which in our case happens to be light itself.