What atheism doesn't have is dogmatic and prescriptive hate. We do not have a dogma telling us we must hate this group of people or that group of people. Now, individual atheists may take on their own particular views and some may be quite angry. I have my moments, just like anyone else, but none of those are prescribed specifically by atheism. Atheism does not prescribe.
And, of course, we argue over and negotiate our definitions - of atheism and that which assails us: theism entrenched in quite often very hateful religion. There are different ideas of atheism among atheists, usually deriving from their individual path to atheism. There are those who left their god-think based on their changing views of morality, or those driven away by the prescriptive dogmatism that is religion, or those who, embracing a stricter standard of evidence like scientific inquiry, question the meaningfulness of ideas that do not have empirical referents. And all combination thereof. I, myself, am a "from the cradle" atheist, and I have views subtly different from those who left a religion just for that reason.
And, of course, there are those who have left their former religions but still exhibit some of the artifacts of that religion, like retributivism or evangelism, and we even have a generation (not just stray individuals like me), who grew up without their parents indoctrinating them into a religion. Some of these have replaced religious prescriptivism with another form of dogmatism, like social engineering mentalities.
We atheists are a diverse and rough-hewn gathering of individuals. Before the internet, we were pretty separate and far flung, without any social functions, gatherings, or cohesion. The internet gave us community and those communities will have any of the issues other human communities share.
