Prior to WWII, college was a (relatively speaking) expensive proposition, only undertaken by those at the top-most rungs of the socio-economic ladder. Non-professional jobs did not call for a baccalaureate degree because there simply weren't nearly enough people with bachelor's degrees in the workforce to make such a requirement at all tenable. That all changed with WWII, and FDR's original GI Bill, which guaranteed a full ride at any accredited four year college. 16 million WWII vets qualified for GI Bill benefits. College enrolment exploded, both at existing colleges, and at the many new colleges that opened in the post-war years to service the explosive demand driven by the GI Bill. As the Greatest Generation completed their studies, there was suddenly a glut of college educated workers in the job market. Sallie Mae and the rest of the student loan/financial aid apparatus were erected to sustain enrolment and continue to make college affordable (at the point of service).
The last couple of generations (The Greatest Generation, Baby Boomers) benefited greatly, in terms of upward mobility, relative to their parents, thanks to their greatly expanded access to post-secondary education. Bachelor's degrees are now so easy to get that all the upper-level professional jobs are saturated with degreed workers, and employers, acting in their own self-interest, are requiring them of applicants for even mundane, low level positions. The Millenials are the first generation whose parents were themselves college educated. Thanks to the greatly increased income their parents have enjoyed, Millenials very often find themselves overqualified for the same financial aid benefits their parents enjoyed. Given the evolution of the job market, the student loan treadmill is Millenials' last option to get a degree, and enjoy even a small fraction of the upward mobility their parents took for granted. A bursting of this trillion dollar bubble is the surest way to break this cycle. Already, the system has evolved to the point that a large plurality of colleges and majors no longer pay for themselves in terms of lifetime earning-power increase. As a late Gen X father of three post-Millenial boys, I say "Bring it on! Burst the bubble!"