From a reader:

Keep in mind that he hates Richard Clarke
Just to refresh your recolletion, Scheuer was the CIA HQ Chief of the “Bin Laden” desk. He viewed Clarke as an amatuer poseur who really knew nothing of significance about counter-terrorism, and was simply an obstacle at the White House who gave Sandy Berger cover from making hard decisions.
Scheuer has always been highly critical of Clarke’s book as revisionist history — taking for himself many of the accolades that really belonged to the work and intuition of John O’Neill. So, to see Clinton glom onto Clarke’s book as a basis to defend his performance was just too much for Scheuer to take, especially given the way O’Neill was thrown under the bus by the Clinton Administration in Yemen.