They need to use him as a spokesman.
If nobody goes to your site, YOU CAN'T SELL ADS...GET IT! I don't go to review sites that have nothing but bad restaurants.
When I'm looking for nice restaurant, why would I want to WADE through pages of bad reviews in order to get the good restaurants? Just give me the good ones FIRST, and I don't even need to see the bad ones. It makes NO SENSE for YELP to highlight the bad reviews. Those are the ones that should be at the bottom.
And anyways, I know this might sound like no difference, but people want to read reviews to FIND GOOD places not to avoid bad ones. Why would you go to a site that did nothing but BASH restaurants & doctors? Sure, you want an honest assessment, but do you have to weed through pages of bad reviews to find the 1 good review? I'd spend my time on the site with the GOOD REVIEWS. I don't see at all how it's in the interest of YELP to fill their site with bad reviews.