Liberal arts degrees are also relatively flat, depending on how you want to count them: the major rise was in business, which accounts for about a quarter of U.S. undergrad degrees. Communications has also risen enormously.
(See Academically Adrift and Louis Menand's The Marketplace of Ideas for more details. Note that the former also finds that liberal arts majors actually make large, measurable improvements in learning over their first two years of college, while business majors, as a group, don't.)
Tuitions have been rising primarily because state governments have been reducing subsidies to higher education -- thanks to pressures elsewhere in the budget, like pension obligations. Generous federal loan policies and capital expenditures on non-essentials like swanky 'luxury dorms' haven't helped.
That's definitely a problem I've seen with my peers. They go just because their parents expect it of them. I can't find the article (it was on HN maybe 6 months ago) that compared college majors in the mid 80's to 2011. While useful stuff like CS stayed relatively flat, the majors that skyrocketed were things like Liberal Arts. Those are the people making college expensive for all of us.
One real way to bring prices down would be to attend community college for 1-2 years. It's extremely cost effective, easily transferable, and designed for working adults so the schedules are often more flexible than traditional college.