It's probably unsustainable to have 175,000 psych and history majors[1] graduating every year with 10-20,000 dollars in debt[2]. (Not to speak of all the business/marketing majors)
I'm not saying that colleges should turn into work-training programs, but there's a huge impedance mismatch between the cost of college, the skills conferred by the degrees that most people get, and the rewards for those in the workplace.
At some point, the average decent public university degree (in a non hard-science) will cease to pay for itself over the long term. Then the only people doing the humanities will be those of a class privileged enough to afford them, which is an outcome that I don't think anyone wants.
Even when you take into account the often generous financial aid packages in the US, costs are still spiraling compared to benefits, especially in the less lucrative degrees.
1: http://nces.ed.gov/programs/digest/d09/figures/fig_15.asp 2: http://www.usatoday.com/money/perfi/general/2006-02-22-stude...