I think you're right, it works both ways, though if you hang around here a while, I think you would agree that it tends to rear it's head on one particular side of the debate
Personally I think it's about faith, or lack of it, we all believe in something right?, none of us can prove it, and as long as we acknowledge that, we can get along- because we might find ourselves on the other side one day.
But if we do not acknowledge faith, we assume inherent intellectual superiority, this 'justifies' ramming our 'superior 'beliefs down other's 'inferior' throats, which can never work
Dawkins "It is absolutely safe to say that if you meet somebody who claims not to believe in evolution, that person is ignorant, stupid or insane"
I don't think he is any of those things, I just think he's wrong, and he's clearly causing himself a lot of stress over the desire for everybody to agree with him.
Stalin, Mao, Il Sung... made very similar statements, and I think their hatred came from the same place- blind faith is faith which does not recognize itself..