Profit is a tax on workers. And, just as in the public sector, that "tax" is beneficial to everyone in the form of increased investment ability, and other, longer-term benefits to workers. This is the essence of the unwritten social contract between employers and employees. But when the tax becomes oppressive, same as in the public sector, it breaks that social contract. Marx pointed out that, after centuries of serfdom and wage slavery, this social contract has yet to be defined. That is the true purpose of a government of, by, and for the people.