You're basically saying good investors don't exist and everything is priced to perfection? This could range from investing in equipment, to expanding in a new business line, to acquiring a competitor and realising synergies that someone else would not have noticed. Putting 1 and 1 together in specific business focus areas might result in 3 for the well trained eye or the smart mind.

Plenty of people are good at investing (understanding how it all ties together, and understanding how they take risk) outside of the public markets. And plenty are horrible (i.e. mom and pop investing in the mutual funds of your bank).