What this article, and many commentators in this thread, are forgetting is that the college/university system is not designed primarily for education. The reason why the college system is tailored toward young adults is because we as a culture have decided that college is the place for young adults to "find themselves." College is often the first time young adults begin living on their own; putting them in a structured institution with their peers is how many kids learn how to "grow up" (in particular, the children of privileged individuals who also want their children to receive some sort of education/job training). There are other issues with the higher education as an institution, but the segregation between older adults ("nontraditional" students) is not one of them, nor is the seeming lack of responsibility found at college (though sexual assault and substance abuse are serious issues that need to be addressed) - it's a defining part of the American "college experience."

It could be argued that you can "find yourself" without college, and while that's absolutely true I would say that it's hard to find a better institution to do so (other problems like rising tuition/loans notwithstanding).