Why do DeGaulle, Eisenhower and Churchill NEVER mention the holocaust in their memoirs???

Why do Charles DeGaulle, Dwight Eisenhower and Winston Churchill never mention the holocaust in any of their memoirs??? 'Crusade in Europe', by Dwight David Eisenhower, 559 pages, 1948 'The Complete War Memoirs', by Charles De Gaulle, 1048 pages, 1950 'Memoirs of the Second World War', Winston Churchill, 1088 pages, 1953