Have to admit it, I'm a fan. I have a great time with this series with my kids. My favorite structure in these books is the part where it breaks into the 8-box sequence for the pigeon to go on a tirade. This is just one example of Willems' control of pacing through use of a cinematic montage style. Again, Willems' animator sensibilities for storyboarding are impressive.
Mostly, I rate this one a four because the sentence "Oh! Look at all those nuts" demands some inference, when it gets just dropped off as the pigeon enters. It comes back at the end of the book. As far as books with a message go "cookies without nuts, please" is a message I can support fully. And brownies, too.