I think the atheists saying the things you object to here are trying to speak to the religious in terms that would affect them and be understandable to them. Still, I absolutely agree that saying something like this reinforces the wrong stereotype that being religious somehow makes you more likely to be moral when what it does is in fact the polar opposite of that. Being religious makes you more likely to support immoral shit due to your brain being switched off and getting answers from outdated doctrines and inherently immoral books.

As you put it - immoral and delusional are perfectly compatible.