It doesn't get my goat, it's not worth getting angry over someone not believing things can be done any way but theirs, it just irritates me that they think they can make those statements and then expect no one to question, much less say they're outright wrong, what they've puked up on the floor.
Just because it's in a book doesn't mean it's true.
Just because it's not in a book, doesn't mean it's wrong.