The tenants of "Islam" are no worse then the tenants of "Christianity". Do we really need a rehash of all the deaths and torture of people all in the name of "Christ". It makes Islam pretty tame in comparison.
The "tenants of christianity" that resulted in the Inquisition and all of the Crusades, had nothing to do with christianity.
While those atrocities were done in the name of christianity, they had no authority to do so from the bible.
Unless the Koran lists these fatwahs for the purpose of being purely historical, like the Old Testament of the Bible, I think there is a major difference in philosophy.