The trouble is consciously rejecting an idea you were raised with doesn't immediately rid you of the various biases that idea instilled in you. And nobody is more susceptible to bias than people who don't think they have any, which describes a lot of people in that sphere. This is where the absurd phrase "culturally Christian" comes from, because they realize the beliefs they were raised with are bullshit, but then they notice that that belief system has all the prejudices that they have (because they were raised with it), so rather than confronting those biases and doing self-crit (emotional self-awareness and humility ew ew gross) they instead just come up with some bizarre twisted rationalization (using FACTS and LOGIC) and accept that. The brain is very good at rationalizations like that and can invent all sorts of convoluted lines of logic if it means fitting in with one's tribe.