A lot of people say this, but a College Education has an excellent ROI when you look at median earnings of college graduates vs median earnings of high school graduates.
Some majors such as accounting and engineering offer even better ROIs. Some entire industries, such as Education, are almost entirely blocked to someone without a college degree. Lifelong earning numbers are correlation and not causation. We've all meet great engineers that did not complete college. Still, as long as college graduates are out earning high school graduates by significant amounts colleges will not have to worry about attracting new students.