A sales person is usually trained on an existing product or portfolio of products (including services). A good sales person might use their exposure to customers for gathering valuable information to feed back into their upstream org. But this is completely different from someone who has to actively shape a both sides of the company, value delivery and value creation, because both need to mature in a choreographed manner.

So you are right in one direction: a good CEO often has to be a good sales person. The reverse does not apply, though.