Because they haven't yet?
Don't forget these are the genetics and culture that took killing to an industrial level.
Do you think 2 generations could completely cleanse them of these proclivities?
During World War II, members of the Muslim Brotherhood spied for Hitler's Nazis in the Middle East.... fought for Hitler as Nazi troops in two specially formed Muslim Waffen-SS Handschar Divisions ('Handschar' is German for scimitar, the curved saber used by the Muslim troops of the Ottoman empire)......
Hitler with Haj Amin al-Husseini, the Grand Mufti of Jerusalem and a close ally of al-Banna, in Berlin, where he lived as Hitler's VIP guest from 1941 to 1945, before joining al-Banna in Egypt in 1946.
The Muslim Nazi troops of the Waffen-SS Handschar Divisions are being reviewed by Haj Amin al-Husseini and by the SS Reichsfuhrer Heinrich Himmler (below this photo)