Why? Very simple. Because the ideas it's based on result in
this.
That's Lac-Mégantic, Quebec this Saturday morning. A freight train hauling over 70 tanker cars full of crude oil exploded right in the middle of the town. Scores are dead, and the place was levelled. So what happened? They don't know exactly, but they do know that because of recent austerity measures at the federal level, the relevant rail safety regulations have been going unenforced - the government has been relying on railways to enforce the regulations themselves. To self-police.
Of course that doesn't work, since companies have no incentive to do so. They're going to shirk and cut corners. And that's why libertarianism - an ideology premised on the notion that companies will self-regulate - is broken: it results in the deaths of scores of innocents, because those companies can't be trusted to self-regulate when there's a buck to be made by not doing so.
"But wait, TSC," you say, "sure companies might fail to do the right thing, but then the marketplace will sort them out! Companies that fail to act properly will lose business! The market self-regulates!"
Two responses to that:
1) There's no guarantee of that. If there are no regulations and
every company has an incentive to cut corners, why wouldn't they all do that? If your company is crap and people want to go elsewhere with their business, but every other company is just as bad, that particular market mechanism doesn't work at all, does it?
2) So the idea is that a company does something bad, people see it, then they take their business to other companies meaning that companies have an incentive to not act badly? That's a nice theory. Too bad it means that people die in train conflagrations before the market acts to correct the deficiency, don't you think?
I mean... honestly. If this isn't an argument for government regulation, I don't know what is. Libertarianism just means more sorrow for everyone, all in the name of a political and economic system that doesn't even achieve what it sets out to do. Bleh.