This is a less interesting statement than it sounds at first. Corporate finance is simple enough that a highly intelligent person can learn what they need to know fairly easily.
A more accurate statement would be: "CEOs must be highly intelligent, and they must understand what their company is doing" -- which might involve technology, finance, or both, depending on the industry.
Chess is simple enough for a kid to learn. But the level of mastery varies greatly among people. Worse, inexperienced players are unable to recognize their own weaknesses or to recognize skill in others.
A more accurate statement would be: "CEOs must be highly intelligent, and they must understand what their company is doing" -- which might involve technology, finance, or both, depending on the industry.