Part of what makes this author so compelling (in addition to her clear writing) is the fact that she was heavily involved with the whole "reform" movement that caused this mess. She knows the ideas well and is very articulate.
So when she says, "I was wrong," and she does say that, it makes the reader more prone to listen why.
Ravitch does not spend a lot of time discussing politics--there are a lot of statistics instead. She presents a very clear and compelling case for why what we are doing now is wrong.
As a teacher, reading this book gave me some hope that we, as a nation, will eventually come to our senses about testing and "accountability."