I don't know what UCLA is doing today, but when I was a student, Marcia Bates taught a master's course, "Information Seeking Behavior," which did exactly that. Returning to school after 10+ years in the field, I was fascinated and more than a little annoyed that my MLS program hadn't included that kind of course. Of course, all of our doctoral seminars discussed these issues.
At LSU, Carol Barry teaches "Information Needs Analysis," which certainly includes the "food-chain," as you call it. I require students in cataloging to write a research paper, using scholarly sources, in which they compare and contrast the information seeking-behavior of a given group with the structure and function of the classification system or subject heading scheme used for that group. My course on the history of books and libraries is essentially an exploration of these issues throughout time -- how and why books and libraries developed in various social and cultural contexts; in other words, "print culture.'
I also address it in children's services, I'm quite certain that Michelynn McKnight discusses it thoroughly in her "Information Resources" and other courses, I expect that Bob Ward includes it in his management courses -- in fact, I'd be extremely surprised if every class we teach didn't, in some way, touch on this to some degree or another.
I'm curious as to what makes you think that this is not standard part of every LIS curriculum today.