Ideas and execution both matter. The real point of “It’s not the idea, it’s the execution.” is to emphasize that idea people (those who dream up an idea and expect others to do the hard work) cannot simply throw their idea out into the world without doing the work of promoting, building, and monetizing it. INTIITE is a useful phrase to apply to people, not products. You cannot really be an "idea person", but instead must be a person who GTD with an idea. People that GTD don't want to have to deal with people that think an idea entitles them to greater equity, hence the usefulness of INTIITE.