Yet another outrageous calumny heaped upon atheists is the charge that we are dogmatic. Why do theists say this? Because we are not agnostic. As I said before, theists insist that we call ourselves agnostic unless we claim to be 100% certain there is no god. They want to box us into this corner so that they can then make the argument that we have asserted a positive proposition and therefore have the burden of proof.
Calling us dogmatic and fundamentalist and other such offensive names that obviously apply with much more accuracy to the religious is their way of trying to bully us emotionally into either shifting to agnosticism or stepping into their burden of proof trap. (They find agnosticism more acceptable because it implies that their "invisible magic man in the sky" theory of cosmology is a serious theory, which it most certainly is not. It is obviously a primitive myth that has survived by hook and crook--literally--into modern times.)
They stick to the notion that atheists believe something most of us don't and that even though atheists have told them that many or most of us do not define ourselves as those who "know" for certain that god doesn't exist.
The dogmatic label is another example of intellectual dishonesty, because there simply is no atheist dogma to be "matic" about--unless you want to argue that it is dogmatic to think that only objective reality based considerations are properly taken into account when one is making decisions that involve other people. That isn't dogma, that is simply common sense and respect for the right of others to determine for themselves whether they want to have supernatural beliefs.
A similar point can be made regarding decisions that affect only the person making the decision. Atheists very strongly encourage others to make such decisions based only on objective reality. We respect the rights of others to make such decisions based on their beliefs, however, at least as much as the religious respect the rights of members of other religions to make such decisions in that manner. In fact, I think it is clear that we respect their rights in this regard more than they do ours or each others.
Simply put, a dogma is a teaching that must be adhered to by members of a particular religion. Atheists have no such teachings. The only thing we have in common is that we don't think that supreme supernatural beings exist. Other than that we are all over the map regarding what we think.