Humanities are by their very nature historical, looking back at "the greatest that has been done, created, or expressed," first primarily in Western civilization but increasingly elsewhere. The great works are intended for audiences who have lived, thought, made errors, lived with the mistakes for a long time, thought better, etc. Past societies were mostly populated by adults. Adolescents are the target audience for today's consumer culture because they possess the traits that marketers are looking for: weak impulse control and a strong desire to satiate sensations that they are unable to define.
So we end up in a world where the Coming of Age story (also known as the Hero's Journey), which is a metaphor for the years between roughly 11 and 17, is the standard Hollywood formula; the focus of music lyrics is obsessional/addictive love, which is the kind of love most people experience before the age of 25; and a world where the phrase "with great power comes great responsibility" is news and is delivered by a guy who is superhumanly strong rather than, for example, a guy/
And regardless of their chronological age, adolescents generally dislike mature art. It serves as a reminder of their discomfort with their identity (which again is a defining quality of adolescence and also makes them much more compliant consumers).
A sizable collection of topics that the previous three generations or so in the industrialized world do not want to think about may be found in the humanities. It is obviously despised. In addition, a lot of it is being taught by perpetual teenagers; you're more likely to find Batman, Twilight, or Star Wars in a general humanities class these days than you are to find anything about how an adult lives, grows, and dies, like, for instance, The Trojan Women, Hard Times, or The Paths of Glory.
Thank you,
Eddie