Imagine someone told you that dragons existed and that they ruled earthly kingdoms and cast spells and wizards flew around the land on carpets, and demanded that you kowtow to their belief, and demanded that Laws be made based on those beliefs, and actively harassed anyone who didn't share in the fantasy - and YOU told them that such things had never happened, that there was exhaustive evidence that such creatures had never existed, and that there was absolutely no objective evidence backing any of their fantasy up.
Now imagine that they jumped in your face for simply pointing out the truth and screamed, "You're oppressing ME!!! Stop trying to tell me what to believe!!!!" while you calmly try to explain that what you just said is fact, not belief, and yet they seem to do their best to figuratively jam their fingers in their ears and continue spouting sheer nonsense while you attempt to have a rational discussion with them about the difference between subjective fantasy and objective truth.
Can you imagine how frustrated you would feel? Good. Then you understand how each and every atheist feels when theists refuse to even entertain rational, logical debate.