There's an assumption that the articles that he's having written are of low quality. It's possible that they might not be, and might be informative enough for users to find out what they might be looking for.
That's not a made-for-adsense site. It's heavy on SEO, and looks indeed like high quality content, but for a different purpose. The content on a made-for-adsense site is designed to look good enough to fool Google, yet not helpful enough so the visitor has to click on a ad link to find something better.
