You're neglecting the facts that 1: we are not operating in a capitalist system. We are currently operating in a Fascist system, by which the government works in cooperation with Corporations, themselves creations of the government, to control the economy. Without the minimum wage, unemployment would go down, probably to 0 involuntary unemployment, which by itself would give the workers more bargaining power.
And this neglects the fact that it's next to impossible to survive on minumum wage as it is. It's telling that we need government intervention just to keep corporations from paying people so little that they can't even survive! If companies were responsible, we wouldn't need a minimum wage in the first place, would we? The system right now sucks, and I'm the last person who'd defend it, but look at how people lived when there were fewer government regulations. All of that stuff was put into place specifically because less regulated capitalism leads to more and more instability and more and more worker abuses. Why would you ever think that eliminating them completely would do anything but embolden the corporations to do whatever they want, when all of recorded history shows that's exactly what they'll do? And what they
still do?
You can't blame every corporate abuse on the government because it just starts to sound ridiculous and completely ignorant of history.
Unions would further increase worker bargaining power (labor unions, not trade unions, there is a distinct and important difference) to the point where they are roughly equal to the people hiring them. Added to the fact that without the government to shield them, the CEOs would actually be liable for their company's actions, life starts to look a little better, eh?
We went over this in the AnCapistan thread and you've still failed to give any kind of an answer - if the corporations aren't responsible to anyone, how is a completely powerless government or some private enterprise with no incentive to do so going to arrest a CEO? Without a government, they are by far the most powerful force in society and could afford private armies and all of that good stuff. I keep asking, but I keep getting no answer: who's going to stop them?
These companies also have a depressingly long and mostly consequence-free history of firing, threatening, and even killing people who try to start unions.