There are a few things I admire about libertarianism, and I do agree that a perfect world would be one with minimal government involvement in your life, provided humans were perfectly moral creatures (which they're obviously not). The problem with the libertarian "hard work" argument is its practicality. In other words, its practicality is its very impracticality. True, hard work goes a long way, and there are very few people in this country that can't achieve basic goals (like graduating college and finding a job) if they would just apply themselves. However, it's just not always that simple. Many of the people who make these kinds of arguments often come from environments wherein hard work (and perhaps even college) is encouraged. What about those people who don't come from such environments? Yes, I agree, they should want to work, but it just isn't that simple to motivate people sometimes who have been raised under different psychocultural circumstances. It's not to justify this kind of mentality, but just to attempt to complicate our notion of easy solutions to everything.
Furthermore, it's fine to say that people should work hard and will make their way in the world if they do so. It sounds nice, and, often this does work for many people. However, what do you do with women who still do not earn equal pay in many jobs even though it's 2012 the last time I checked? How is a single mother supposed to always make ends meet when this might be stacked up against here unfairly? Also, what do you do with minorities who don't always get hired to certain jobs? And yes, I know about Affirmative Action, but let's be honest, there are still some racist employers, even if it's as seemingly benign as simply being put off by an applicant with a name like "Shaniqua" or "Tyquan"? Hard work might have gotten these individuals past college and might have gotten them many things, but things could possibly still be set against them in some circumstances.
P.S. I don't need any reminders about Affirmative Action. I am completely aware of the practice, and, no, I don't always agree with it. Yes, sometimes it has been unfair to whites, but, then again, a higher percentage of whites come from environments that encourage college graduation than most people of color. I fully agree the middle to upper-middle-class minority family should not need affirmative action.