I think this is a bit of an overstatement. Another purpose of companies is to provide the benefits of a command economy (e.g., the ability of a great leader to jump from a local to global maxima) with less of the dangers of a command economy (great leader robs/kills you, poor planning screws everyone over).
E.g., central planning in the food supply can work reasonably well, but this is hardly guaranteed. Market discipline gives us the benefits of McDonald's 5 year plan, but a McBankruptcy rather than Soviet Union style food shortages if the 5 year plan fails.