In its 166+ year history, Scientific American has changed and evolved in different directions many times. There were periods when it was a densely-packed, jargony, almost unreadable publication aiming for a small niche of super-geek readers, and there were periods (like the last couple of decades, fortunately for all of us) when the magazine went back to its original mission of being a premier popular science magazine, accessible to readers of all backgrounds. There were times when technology, engineering, patents and "hard sciences" dominated its pages, and also better times (like now, just look around!), when the publication adopted a broad coverage of all areas of science.
But no matter what period it was, people have read (or tried to read, or pretended they could read and understand) the magazine in its entirety, regardless of the subject matter. This includes some readers who themselves were prominent leaders in their scientific disciplines. And sometimes they'd say something about that reading habit in public. Here are two examples from anthropology.
Claude Lévi-Strauss, one of the founders of Anthropology, said, among else, this in his 1977 Massey Lecture:
Let me start with a personal confession. There is a magazine which I read faithfully each month from the first line to the last, even though I don’t understand all of it; it is the Scientific American. I am extremely eager to be as informed as possible of everything that takes place in modern science and its new developments.
Alfred Gell, another prominent anthropologist, wrote this in his 1999 book (really a collection of essays) The Art of Anthropology: Essays and Diagrams, on page 24:
Thanks to my brother for bringing my attention to these two quotes.
If you find similar quotes by other notable people from the past, let me know so I can post them here.