Dont insult religion.
;-)
Once they assign morality to the acts based on their beliefs, they really HAVE made a religious statement. It begs the question that needs to be asked: “If you see this as a moral issue, who is the source of this moral proclamation? Who is your “god”, and where does he proclaim the morality of this issue?
You point is quite right.
Some 50+ years ago, British analytical philosopher G.E.M. Anscombe chastized atheist ethicists who think there really is no right or wrong still use terms like "should" or "ought" or "moral law" as if one could be obliged to commit sodomy, or torture, or rape, or murder, if there were a good enough reason. Its as if God Almighty had said, "Thou shalt not commit moral abominations unless thou art really, really, REALLY tempted."
If one does not believe in a divine Moral Lawgiver, one should be honest and stop talking about big words, big authority-words like "should" and "ought" and "moral law". Its dishonest. Otherwise, you are like a person who uses a big authority-word like "verdict" even though he has abolished judges and juries; or a person who claims to be an expert on ribs and joints, when he denies the existence of bones.