A deep, carefully argued, carefully research report from Debt and Society makes a strong case that sky-high tuition (and brutal, lifelong student debt, up 1000 percent in 15 years) is not primarily caused by bloated administrations or high professors' salaries. The explanation is a lot more banker-y.
Cuts to public spending drove universities to hike tuition, and the students made up the difference through loans, which benefit financial institutions. The university-as-business ethos that followed drove administrators to float lucrative (for the financial sector) bonds to create showy physical plant for their campuses, further driving up the cost of tuition and the finance-sector revenues from student debt. It's even worse in the for-profit university sector, where all of these financial shenanigans and the attending lifetime of debt are accompanied by "dismal graduation rates."
The spending on actual education – classrooms, faculty, etc – has held steady through this period, but ten percent of America's $440B annual post-secondary education spend goes into investors' pockets.