As I see it, the main problem with college is that we as a society have put all of our eggs into a basket which is not owned by we the people (the public). If you would like to see a future in which all Americans go to college, then the cost should be spread across everyone. If you don't, then, I think we have different views of what the future could be. We should go back to free tuition, at least for state colleges, because an education requires so much more material than it did a century ago that stopping at K-12 was shortsighted/irresponsible, and now other countries are eating our lunch. An analogy is the private prison system: when we began outsourcing incarceration we created an incentive for prison industry lobbyists to interfere with the criminal justice system. Show me a private school that costs less than a public one.
Student motivation is a red herring. I've met just as many slackers who didn't go to college. In fact I would go as far as to say that pure book learning without introspection is not conducive to the human spirit. The best things I learned in college were how to redefine myself, and how to explore alternate ways of seeing the world. In essence my conscious and subconscious minds both grew as needed. Sometimes I wish that the US didn't have such a puritanical stance on recreation because we are in danger of creating a dystopian, authoritarian future. I wish with all our wealth and potential we could live more like europeans and invest in culture and the human experience. College isn't a trade school, I mean, who goes there to study besides freshmen?