Originally posted by Teinosuke
The question would not be what industries "need" government industry, because this is a question of what the state can pragmatically acquire at any one time. The government could and should choose to target whatever business it thought might be a profitable state asset; but because this would take place on the open market, no state coercion would be involv ...[text shortened]... a state franchise, they would in part be funding their own health care, education, pension, etc.
Let's use your example of the government creating a soda company. Is it fair for the government to pay for advertising that says their soda is better because it is government owned? It would use presidential speeches, governmental interviews to promote itself. The government would use political volunteers, tax free donations, promises of other future jobs and everything else that government can offer to make sure it can beat down its competition.
It is inconceivable to think that Congress would not make laws using its industry to cross promote other goals (union activity, environmental, healthcare minimum wage, progressiveness) There would likely be laws to promote its product in the governmental model. For example there would be "taxes" on the old company if it does not meet health standards, or give enough health insurance pension benefits to its workers or have a sufficiently progressive pay scale or have enough women or minorities or use too much foreign labor. Congressman would make deals to help constituents instead of what is needed.
Government would not care if it hurts the old company or its stockholders. Government simply expands so it has more influence. I cannot imagine a way to more quickly forego our rights than to allow government to run everything. It will mandate what we buy, how we produce it, where we produce it, how much everyone gets compensated.