College tuition is the perfect alignment of the stars, economically speaking. There's no new supply of public universities. Reputations are extremely sticky. A college degree is often a job requirement. The highest paying jobs mostly recruit out of the top universities, so students are extremely price inelastic at certain levels. The government subsidizes student loans at artificially low rates. More and more foreign students want to attend US universities. Etc.

Hell, it's almost a surprise that college tuition hasn't grown at an even faster pace. In ten years this is going to become a serious national issue and I think you'll see the federal government step in to cap the tuition increases. It's gonna happen.