My opinion may be regarded as biased, as I work in a content marketing agency. However, it's always intriguing to see people debating on the topic, as it's the most common question we get from our prospective customers.
What is most of the times neglected is the fact that the client - the entrepreneur - never disappears in the wind. The process of writing an article/e-book/white paper is one in which content writer and company representative work hand in hand. There are several drafts at work before a final version can be published.
And of course no content writer will ever be able to get the exact thoughts of the entrepreneur out on paper. But it's the best compromise in an equation in which one side has little time for writing and the other little insight into how the company works (P:S: most content writers will take weeks to understand their client before actually getting to work).