Libertarians are often accused these days of being utopians. Sure, the free market would work in a perfect world, but in the real world there are predatory businesses and other such monsters crawling under every bed. We need the government to look out for the little guy, or else who knows what will happen to society?
But while libertarians may on occasion speak too highly of the virtues of spontaneous order, I think the reality is that conservatives and liberals buy into a vision of government which is naive in one extreme or another. On the one hand, conservatives talk often as if we get the government we "deserve," as if somehow if we were just more true to our traditional values we would have an ever-thriving society. On the other hand, liberals seem to think we need to "take back" the government, as if we, together, united, can change society for the better.
I think the libertarian critique is the most profoundly realistic vision of government you can have. On the one hand, no, we don't necessarily have the government we deserve (for better or for worse), because we have not nearly as much control over government's formation as our democratic institutions would suggest. On the other hand, there is no way to collectively take charge of government--such massive collective action simply doesn't exist in the real world.
Don't get me wrong. Values matter, and social movements make a difference. They just don't make the difference we expect. Libertarians instinctively believe that government should always be reformed, and we also expect that no matter how much reform takes place it will still never be perfect. The role of the individual in politics is not so much to take responsibility for government as it is to take responsibility for his own beliefs, his own actions, his own civic ties, and his own vote. If the government turns out bigger or worse than it ought to be, it's not the fault of the individual. But it is the fault of the individual if he takes the defeatest attitude of one so victimized by the system that he fails even to better his own situation.
I've been accused of being an idealist before, but I think that's because people underestimate how dangerous the real idealists are. The real idealists are the megalomaniacs in Washington who actually believe they're doing what's best for the country. God save us from the idealists.