I just flipped to the back of John Sexton's Recollections (which is getting very dusty) and re-glanced over the tech pages. With all due respect to this revered photographer, even for his own students, is there anything more arbitrary than f stops? I've seen interviews with him, he's a very thoughtful guy, and I'm sure the addition of that information is nothing more than a genre convention. I've only ever observed it with traditional landscape photographers, who are usually engaged in 'workshop culture', where it might be encouraged to jot this information on the back of every print. It's quite a finicky habit then.
This Craig Varjabedian guy linked (whose images are very nice incidentally) clearly comes from the same school as Sexton. I think it comes down to the old 'taking/making' anxiety of this classic landscape genre - as if focal length, speed, aperture, developer etc. are somehow 'evidence' which can be supplied in the event of being challenged!