Well, if you look at it another way, the family could be upset because they're slanting what he said.
Don't get me wrong, I'm sure it's fairly accurate. And the picture they paint is clearly someone who could have created Charlie Brown. But I think, like most biographies written soonafter the subject died, there's lots of room for bullshit.
I know the family worked with the author, and of course there are going to be some things that are slanted due to the fact that the author appears to have developed a thesis about his life early on in the process. But we both read that Q & A in one of the Peanuts collections that Schulz had done in the early 90's. The person portrayed in the book seems very close to the man in that Q & A. As Oprah first said about James Frey, I think "The essential truth" is there.
I'm sure you've seen this but Monte Schulz posted about the book...
http://www.cartoonbrew.com/books/reviewing-schulzAll things considered I thought it was pretty balanced, and like I said, it can't be easy to hear negative things about your recently deceased dad in any instance. And there were things (specifically involving his daughter when she was a teen) that just didn’t need to be in that book AT ALL.
I find it sad that someone in who’s work I took so much comfort when I was a child was so unhappy so often. THAT is why I was happy to see ole Chuck get the giant soda bottle.