Because he is likable, funny and he always has on a good mix of guests. He's the only thing I watch on that channel, but something I appreciate about him is a lack of any mean streak unlike his contemporaries. It's a trait I appreciated in John Stewart as well... even when "slamming" a guest for a stupid comment, he delivers it with affable humor that lessens the blow while making people laugh at the comment instead of the person giving it. Something that's been lost in modern society is the ability to confront an idea instead of the person sharing it. The former opens up new debate and thought, while the latter ensures cessation of both. A good moderator knows this, and if nothing else, Guttfeld is an excellent moderator.