Actually, the author is clearly stating the causal relationship. He is pointing out that free market fundamentalism is the cause of the crises and Business schools are the cheerleaders for free market fundamentalism.
Now, I personally do not agree with that argument, but your criticism of author's argument is unfounded.
Perhaps some B-schools are the cheerleaders, but I never saw it where I was. Economics departments are where that particular meme came from, and they don't actually teach economics in B-school except tangentially.
My experience is the same. I think people are confusing the macro (economics) with the micro (running an actual company). Business schools focus on the micro and in doing so very rarely address economic systems as a whole.
To but it a different way economics is about how the rules of an economic system are created. Business school is about teaching the student to work within the rules already created in the existing system.
Now, I personally do not agree with that argument, but your criticism of author's argument is unfounded.