I am reasonably sure that if the question were about beliefs that are common to theists (or common beliefs held by theists) that said theists would also take this as an attack.Here's one irrational thing I see several atheists doing right now: thinking that everything someone says about atheist/atheists/atheism, including questions as well as statements, must be some kind of an attack.
Lumping people who hold many disparate beliefs but happen to have one thing in common, such as belief or lack of belief in god(s), will tend to get people riled up. Some atheists are on the left of politics, some on the right. Some believe in ghosts, some do not. Some swear by homoeopathy, some think it's mumbo-jumbo. Und so weiter. And the same goes for theists.
It's not irrational to object to false generalisations.