Totally agreed, Nic! I hate it when someone asserts that religion deserves some kind of respect, regardless of the stupidity of a particular assertion or assumption made my the religious person, based on faith, rather than reason, research and/or evidence.
Sometimes, simply questioning bizarre and superstitious ideas is viewed as hostile, when really, all you're doing is trying to get someone to use the mind or re-direct faulty thinking.
Realizing that someone's assumptions are faulty isn't arrogance, but it's easy for people to feel that it is when you start showing them things they'd rather not see or know, especially if it brings into question some cherished thought or rigidly observed and irrational practice.