Academia and "the arts" have never been solely about the collection of knowledge for knowledges sake. Generally academics and artist have had patrons of some fo

Academia and "the arts" have never been solely about the collection of knowledge for knowledges sake. Generally academics and artist have had patrons of some form who pay for a specific project, which is used to subsidize the academic's other endeavors. History definitely falls under this umbrella, first with kings wanting their accomplishments recorded for posterity. Academic military history grew out of the practical need to study tactics. Since that need is much declined, so too are the universities offering course in the field. You still have your collection of purists who study for the sake of study, but the number who do it because they are seeking to apply it to current issues has decreased.