You mean to tell me you've never felt that way about a bad review of a game you like? Imagine creating a game with a massive budget, pouring all of your ideas and hard work into it, only for people to say it wasn't what you promised. What a useless statement that is. I think most of the time, when developers promise the next stage in the evolution of videogames, they're describing their own feelings about what they're working on rather than what the gameplay itself offers to players. It might be revolutionary, it might not be. It doesn't have to be revolutionary to be great. While I don't consider myself a fan of Molyneux (in fact, I've only played the original Fable and the Black & White series, and wasn't crazy about the latter), I do feel that he's at least passionate about what he does. A lot of these interpreted "promises" probably stem from his enthusiasm for creation during interviews.
I think he has to respect other developers as well, having a child who obviously loves videogames. When I watched the video, I didn't feel it was just a plug for Fable 3 at all. I interpreted it mostly as a salute to Valve.