It is a provocative claim that I think the book succeeds in showing to be true.
It is a worthwhile book and, even if you disagree with it, I think you'll find it intellectually stimulating. If you think you'll read it, I'll happily buy you a copy, just PM me.
Sure, equal is unfair. But that's not what people who are concerned about rising inequality are asking for. They mostly want inequality to stop from rising. So what's the point of showing that equal is unfair?