Why are Atheists so bitter?

I mean why are they so mean and bitter. If you are a religious person and believes in God They flip out and go Charles Darwin on your azz. They clearly have a thing against God, cause from what I've read so many Atheists have read the whole Bible ( which I bet is a lie ) and they hate him and disbelieve in him. They act as though if a person was Religious and murdered millions in war, genocide, and etc. Then it is Religions fault. But what about Stalin who was a Atheists and killed over 2 times the amount of the victims of the Holocaust but they don't want to be blamed, yet they blame religion fanatics on Religion it self. Also Stalin was against religion very much. He believed if Religion was gone that he would be able to control the people easier so he tore down all religious buildings and killed anyone practicing religion. So yeah he did hate Religion cause he was a big Atheist. So are you guys no Better than us, yet you want to seem better?