I've seen this used as a critique, where all the western chauvinist colonial brainworms that are present in Christianity are still present in atheism even though the theological justification isn't there (and many of those atheists considering themselves morally superior to the Christians that they repudiate).

I think in my lifetime I saw Dawkins say he was culturally Christian just after the invasion of Iraq, and it seems much more a declaration of his "side" and a rejection of Islam, but I think it became more common to say about yourself around the same time gamergate atheists became tradcaths.