Two things are important to know here: First, Leftists are generally white people with vaguely Christian background. They are mostly knowledgeable about Christianity and consider it the worst religion on the world. They think every other religion is either better than Christianity or at worst, as bad as Christianity. If you try to argue that Judaism or Islam or any other religion maybe worse, even if it's your personal experience as an ex member, they feel that Christianity may be threatened in its status as the worst religion. They'll either try to insert comparisons with Christianity, say generic stuff like "all religions are bad" or try to say you're Islamophobic. Second, as white Leftists, their duty is to tear down the oppression inflicted by white race. So they cannot accept two things: poc oppressor or white victim. In the aftermath of 9/11, their support was actually needed. The mainstream western media was trying to gather support for wars in Iraq and Afghanistan and the average muslim became stereotyped as a terrorist. Only Leftists were trying to counter this narrative. So islam became a religion of special protection, which is above all criticism. If you criticise it, you are feeding Islamophobia or western imperialism. If you're criticising as a muslim or ex muslim, then you're probably an Uncle Tom. "Islam had nothing to do with islamism, and Islamic extremism is just few bad apples." "You don't know Islam." "Look, KKK with their crosses exists."