Remember the struggles involved in getting the "ibid.'s" and "op. cit.'s" right on your research papers? Some teachers staked their reputations, and their students' futures, on mastery of the arcane art of footnoting.
Now, it seems, that intricately wrought edifice of scholarship is being eroded by the dynamics of modern book marketing. Scholarly writers, and the people that publish them, are finding that the general public could care less about footnotes - and more and more of their works are being aimed at that public, instead of at peers in academia.
So, many books of bona fide scholarship, by people whose credentials few would challenge, are being produced without those added hundreds of pages to incorporate all the material that wouldn't fit into the main text, or to take issue with the conclusions of other scholars.
This may be a victory for readability and greater economy with words. It might even drive learned bombast and showiness into retreat. And it certainly dangles a Faustian temptation before learned scholars: 'give up the credibility of footnotes and we can offer you higher royalties, a larger audience, and greater fame.'
But we shouldn't cheer too loudly. In some books, the footnotes provide invaluable information and insight, as well as confirmation that a writer knows his stuff. And most books with notes are arranged so you can take them or leave them, depending on the time available and your own curiosity.
Finally, maybe all that classroom work - learning how to substantiate what you put down on paper - had its purpose. Students may not retain all the Latin fine points, but they may be left with an appreciation for substantiating a thesis or argument. In those trenches of scholarship - versus the world of book publishing - footnotes will probably endure.