That's a really odd argument. Governments wield power, real power. The power to make laws. Think about what a law is, it's a way of compelling people to act a certain way using violence or the threat of violence if you refuse.
Governments can raise armies, forcibly expropriate money from people, they can place people in solitary confinement and on occasion have engaged in mass violence and genocide.
Corporations can't do any of that. They are therefore in NO WAY SHAPE OR FORM analogous to a government. Until a corporation can enact laws and engage in violence, this analogy remains quite silly. The best a corporation can do is fire someone, or give money to a political cause. They're not angels but I can't really see a corporation on the world scale as evil as our own government, which has invaded a number of other countries and has engaged in a campaign of eugenics, forcibly separating young children from their mothers.