I guess I was thinking of the first few weeks/months of a startup where all the efforts are really around building the product. What does the business guy do? Definitely there are things to do, but if you had to dedicate all man hours to something, building product would be of paramount importance.

And when you think of technical founders like the Google guys, Bill Gates, etc, they started as technical and acquired the business skills as things developed. So yes, business skills are super important. But they can be acquired.

I'm not so sure that a business guy will just learn some technical skills in the early days of a startup. So the tech guy can learn business, but the business guy can't learn tech.