The supply is HUGE, there are 1.8 million bachelors in the US every year awarded. The demand isn't driving the prices higher, the supply and demand are both increasing.
see this:
https://americanheritage-dev.byu.edu/Pages/GamesandActivities/Supply-and-Demand-Interactive-Chart.aspx
if both supply and demand were to increase along the x axis, the price equilibrium would stay constant
this is visualized here: see the 'increase supply/demand buttons'
http://college-cram.com/study/economics/supply-and-demand/equilibrium-curve-shifting-the-curve/
Also, government subsidies are not a factor in the increase in tuition. Public funding for universities has slackened, causing universities to seek other forms of funding (i.e. jack tuition up at unprecedented rates)
or
The current trend is unsustainable. Assuming no changes, there will be a day where paying for school will be financially irresponsible. The benefits of getting a degree will be outweighed by the sheer cost. A seismic shift will occur: young people won't go to college, and the US workforce will immediately become obselete.
I'm not saying go full Bernie, but this IS a huge problem