I agree, and I'll add more to it. In a very small company, there simply isn't enough space for any individual team or segment to diverge significantly from the overall success of the company. When your company is very large, often the needs of various sub-groups might not be in alignment with overall company success, even if they're still trying to make money for the company.

A great example comes from this article. The group in charge of the Pentium product line would not be thrilled to see the Celerons launched, since that would cannibalize their sales. Obviously for long term success of Intel this was the right move, but from the perspective of the Pentium team this might be a horrible idea.