This actually reminds me of an interesting observation in Homage to Catalonia by Orwell. The book is about Orwell's personal experiences in the Spanish Civil War. The particularly interesting bit was about the organization of some of the anarchist forces fighting against Franco. Essentially, they did not have any centralized organization at all. Even a military force can be organized like Valve and not in an authoritarian manner.
Unfortunately I don't have the book handy to find the pertinent passage, but it really stood out. It makes me wonder how much of the military-style management is due to necessity and how much is due to tradition. Of course, the fascists won in Spain, so this is hardly a great example, but there were too many other factors at play (e.g. support from Germany) to make it conclusive.
I don't buy that the military is required to work that way.
Take a look at Iraq and Afghanistan to see how many losses are inflicted on the superior military by groups who are not organized in any traditional military sense.
Do you think they would be more effective if they wore uniforms and had a formal command structure?
Some businesses are required by nature to be military-like - logistics for example.