You hit the nail on the head. It's all about personalities. You don't want the CEO to be the business manager running day to day business and the office, or for the CEO to do the scientific work. On the other hand the scientists should not run the business. And business managers should not be the go between the business and the BOD.

The CEO should be like in the center guiding all these people in the right direction with an overall view of the goal. But in small companies these lines get blurred.