You hit on the meaning of liberal multiculturalism in a nutshell. Who are we to judge the Arabs for their racism, their Judeophobia, their fear of women and their contempt for the West? To liberals the fact they are backwards and full of fanaticism is exactly why they should be elevated to the same moral level as Westerners. Of course its morally obscene and an insult to the truth but multiculturalism denies the evident fact that yes - some cultures are morally superior to others.
"Show me just what Mohammed brought that was new, and there you will find things only evil and inhuman, such as his command to spread by the sword the faith he preached." - Manuel II Palelologus
Ah, and so we have the kernel, that which is wrong is made right and that which is right is made wrong and all is seen as though faintly and obscured as though through a clouded looking glass.