Mark C. Taylor, the chairman of the religion department at Columbia, writes in a NY Times op-ed:
[Y]oung people enroll in graduate programs, work hard for subsistence pay and assume huge debt burdens, all because of the illusory promise of faculty appointments. But their economical presence, coupled with the intransigence of tenure, ensures that there will always be too many candidates for too few openings.
But the question is, if everyone knows that graduate degrees (excluding professional degrees) are such a bad deal, why do so many enroll?
Well, I guess the answer is that SWPL culture highly values liberal arts graduate degrees, and U.S. society encourages people to have an optimism bias (no one in America likes a pessimist), so if only 10% of graduates get a decent job, 100% of students anticipate that they are going to be in the top 10%.
There's also the factor that many of these students have rich parents, so they don't really care if they can't find a job, their parents will carry them.
Maybe, the real mystery is how can the university faculty look themselves in the mirror each morning knowing how they are screwing over their students?