This book is written by a white person for other white people. For progressive white people. While I'm not white, I still learned from this book. I recognize that some of the things she explained here apply to me - and intend to work on those things. And I also identified with many of the things she heard from people of color, which she presented here.
The book explains a bit why it's so difficult to talk to some white people about race. She's not saying people are bad are participating in a racist system:

“If your definition of a racist is someone who holds conscious dislike of people because of race, then I agree that it is offensive for me to suggest that you are racist when I don’t know you. I also agree that if this is your definition of racism, and you are against racism, then you are not racist. Now breathe. I am not using this definition of racism, and I am not saying that you are immoral. If you can remain open as I lay out my argument, it should soon begin to make sense.”

I wish I could make some people I know read this. But sadly the people who probably need to read this the most are the exact type of people who never will. (Or who will act defensively and try to tear it apart). It's definitely just a first step - but it's great as a first step.