But why does he care about any of that? Without religion to create and guide morality, why as an atheist does he feel concern about either the rest of current humanity other than himself or the future of humanity? That morality is rooted in religion; I'm not saying atheists don't have morality with respect to themselves within society as part of a societal code, but I don't see how their morality spreads to a concern for others without the religious undertones. It is like he is trying to take the positive aspects of religion because it conforms with his beliefs while at the same time saying they don't exist. His whole stance seems pretty logically flawed to me (not atheism itself, but actively promoting atheism).
Why doesn't it spread?
You don't need religion to know that doing bad things to people hurts them and those around them, Helping people, loving them, sharing and teaching have nothing to with religion. They are about humanity.
Promoting atheism is no different than promoting a religion. You are sharing your beliefs with others just as they would be.