In my opinion, the gossip news blog and other unadvertising friendly niches like jokes, quotation, rock climbing blogs etc shouldn,t be allowed to sign up to the Google adsense program.
The traffic that those unadvertising friendly blogs send to the websites of the Adwords advertisers, have a very low conversion rate. For example most of the people who often clicked on the adsense ads displayed on a gossip news blog may just do so to see what the ads are all about with no buying intent and so those clicks won,t yield any return on investment for the Adwords advertisers.
The main duty of bloggers in the Google adsense network, is to convert web users in to potential customers or clients for the Google Adwords advertisers so that they can get a high return on their investment. Quality traffic is what the Adwords advertisers want and not quantity traffic i.e. traffic that doesn,t converts.