I'm a little uncomfortable with rating this--it being a satirical children's book and all. 
 Instead, I'm looking at it as an illustrated book of poetry, aimed at the hearts, minds, and wallets of countless exasperated adults who happen to call themselves parents. 
 This is a work of empathy and comedy, tenderness and aggravation. (And when narrated by Samuel L. Jackson, it's downright hysterical.) It's a sort of vindicating acknowledgement as well--a nod to parents who are doing their best, but who also fight that explosive sense of accumulated anger toward the sometimes nonsensical offspring they hold so dear. This book has verses in it that all parents can relate to, and certainly have thought...in some form or fashion. 
 We all wear down at the end of the day. Even the Mary Poppins among us sometimes reach critical mass. This book is a literary pat on the back, and a cathartic--if not somewhat crude--reminder that you're not the only one scaling the proverbial mountain of parenthood. 
 Take it for what it is. Laugh. And then, hide it well from those little linguistic sponges you call children. ^_^