Because their entire sense of being relies on their story to be true, those of us who know better, are a threat. Their "What if" is unthinkable to their kind.

What kills me is their penchant for questioning our morality! If they think that we cannot be moral without religion, it begs the question "Without their religion holding them back, would they somehow feel "liberated" and express pent-up amorality? Of course Bakker... Swaggert... Copeland... Osteen... Dollar (ETC.!) don't let their religion stop them from being amoral pricks!

Because they're stupid

We are, by our very nature, a threat to their entire belief system.

Because they are indoctrinated by their churches and religious leaders to obey.

Because they are morons, perhaps ???

Because they know that what they believe and preach is irrational and small minded so they have to try to bully the other side. That's the method they use - and that behavior is emboldened by the behavior of their civic roll model. Fear, ignorance, bigotry and hate dominate their perspective.

do they have to comment at all?
Because they are religious fucks.

Question asked and answered in your OP

They don't like people who "Think" for themselves.Or oppose their " Beliveing"