With respect, a partial theory on why atheism turns people off

I'll make it short and simple as possible, and I do mean this as food for thought and to spur discussion, not to start a flame war.

Atheism is based in rationality. Problem... humans are simply not rational. Some are more rational than others in a given situation, but, from what we understand of human psychology, we basically think first with our emotions and then build empirical evidence to support what our gut says.

Atheists then just appear to be cold. As if they just don't want to believe in magic or miracles. Ever notice the difference in tone of response when someone says they are atheist (closed) vs agnostic (open)? It doesn't matter that you could be Joseph Stalin or the most generous humanist ever to exist, you are seen as someone lacking the warmth to hope for such things.

Atheists are basically the ultimate Debbi Downer and that coldness makes you somewhat suspicious to the rest of the world.

TL/DR - Walking Dead Reference - You are the Shanes of the world. It scares people.