A lot of this has to do with the fact that a lot of students go into severe non-bankruptable debt to go to college. Of course a sub-story is that some of these degrees don't lead to obvious areas of employment.
But esoteric degrees have been around for a while now. But it didn't used to matter so much. There was work to be done, and history, or philosophy majors were thought of as being trainable enough to get a lot of jobs done.
One little secret is that there just isn't a lot of "smarts" works to go around. So the competition is greater.
The Declining Fortunes of the Young since 2000
Beaudry, Paul, David A. Green, and Benjamin M. Sand, American Economic Review, 2014 (hat tip: MR)
The data reveal a clear break in 2000. Between 1992 and 2000, each successive entry cohort has a higher share in cognitive occupations at the outset of their working lives, with the proportion increasing by 0.1 between the 1994 and 1998 cohorts. After 2000, with the exception of the difference between the 2004 and 2006 entry cohorts, each successive cohort has a lower share in these occupations, with the share at entry for the 2010 cohort being approximately the same as for the 1990 cohort. Given all the attention that has been paid to growing demand for cognitive skills, this complete reversal is striking.