I use yelp when in a new city to find restaurants and have been favorably impressed with its ability to weed out the wheat from the chaff. I would definitely be concerned if Yelp were strong arming content to make money.
At first when I was reading this, I couldn't help but think why Google's Adwords (which I heartily love) doesn't strike me as seedy, but I guess it comes down to how the service is sold. Adwords is opt in without any pressure and a lot of tools that at least make me feel like I'm optimizing my buck. I think if I were called by an Adwords rep and asked to spend more cash or else my pagerank "might go down," I'd feel just about the same as I do about the hypothetical Yelp sales practices.
That said, I'm with you dpifke, it doesn't help the credibility of such an incendiary article that it appears in a lesser-known publication.