i just looked at the tittles for about the top 200 post on r/atheism right now and 1 was about Islam (an ex-muslim complaining that libs were calling them Islamophobic) and one talking about all abrahamic religions, most were about the concept of religion or christianity, and in my own personal experience being very far into the entire skeptic "movement" back when it was an actual thing, i think that while Islamophobia was around it wasnt core to whole thing and most people were concerned with Christianity much more than other religions.

dont get wrong reddit atheism is mostly a western and specifically and english speaking thing, that is not explicitly leftist so it reflects that in the people who take part so there more racism and Islamophobia and everything else than u would find in other groupings of people but it certainly never seemed to me like reactionary views were core to it or that it was built on them.