This line refers specifically to the voluntary sytem of education, but it's just as applicable in any other context.
Even when the socialist utopia is in place and operating, human beings still look out for their own interests and behave accordingly. Socialism tries to re-engineer human nature, but nature refuses to be engineered. It simply is what it is.
That's why socialist societies must always become totalitarian and police states. It's only a matter of time.
Remember, as Michele O. said, "Barack Obama will require you to work. He is going to demand that you shed your cynicism. That you put down your divisions. That you come out of your isolation, that you move out of your comfort zones. That you push yourselves to be better. And that you engage. Barack will never allow you to go back to your lives as usual, uninvolved, uninformed."
That particular statement of hers sent chills down my spine as it must have others.