Why do people go to grad school? It all depends. In "the humanities," people generally go to grad school because they like to smoke marijuana, or because they dislike the prospect of finding a "real job," or—and this one is key to the whole grad school house of cards—because they "want to teach." The elusive and illusive prospect of a career in academia helps many kids justify spending tens of thousands of dollars on a graduate degree that qualifies them for no other jobs. Strangely, people who major in fields that have actual applicability to the world outside of college campuses have other career goals.
Inside Higher Ed brings us a new study showing that grad students in the hard sciences (some of America's Realest Majors) find the prospect of an academic career to be less and less attractive the farther they go in school. HYPOTHESIS: Because they can get real jobs.
Whereas grad students in The Humanities presumably find an academic career equally appealing at all times because, where else are they gonna go? There are only so many jobs out there for professional short story writers. (Zero.)
In conclusion grad school is largely a Ponzi scheme.