The standard libertarian assumption is that government stands in the way of the free market, and that if the government would just get out of the way, then the market would flourish and make all the right decisions. It is an argument that the government should be drownable in a bathtub in order to make a better system. When you ask a libertarian what recourse someone would have in this system if they are abused by a private business, they say they such businesses that abuse their customers will eventually die out. People will stop patronizing businesses that do wrong, or customers will band together to form boycotts.
Thus the idea that business will be stronger than government but weaker than individuals - though granted, weaker than individuals acting deliberately or otherwise in tandem. What's wrong about that? How does that not represent the libertarian ideal? After all, if government would just get out of the way, then things would be better, right? Individuals don't need the government to deal with large businesses that harm them, right?
"the unchallenged assumption that government has to be more powerful than the individual." My ideal system is one in which the individual, the government, and private businesses all have checks on each other of about equal power. Say, for example, when many individuals are wronged by a company in a small amount, they should have the right to file class action claims to settle those disputes. In the realm in which a large employer does wrong with its employees, those employees should be able to unionize to represent their interests. If a government does wrong with its constituents, there should be sunshine policies to ensure that the public knows what's going on so that they can make informed decisions at the voting booth. I don't see how my sig has anything against that.