Anti religious was(is?) pretty fundamental to the “New Atheist movement” from the latter aughts and early teens from this century. They don’t represent atheism as a whole but a decade ago they were highly visible and did a lot to screw up the connotation of the word “atheism.” I think it’s possible to argue in good faith that religion is ultimately a net harm (which I wouldn’t), but there is also a bigoted and ignorant way to do that which was far more common. While the “a” in atheism means “without,” there used to be quite a significant presence of those who manifested the belief that it meant “against.” I’m sure they’re still around, but they don’t seem to be as constant an annoyance as they used to be and many of their figureheads moved on to support right-wing politics targeting the religions they hate the most.