Sidebar is not an unusual place to place author bio and it is definitely enough for me.
I say that it is a bad writing style because I am assuming good faith. I assume that the positioning of his bio is merely unfortunate and not specifically chosen to reduce the number of people who read it, and that the article is not actually trying to deceive me about the author. I think it is obvious that coming across as astroturfing to some subset of your readers when that isn't what you're trying to do is a bad thing.
Oh please. Most blog authors barely manage to fill out an About page, let alone a sidebar and a big subheading at the top of the page that says who their employer is. If you're going to claim to be "assuming good faith", how about actually doing so?