Just like how some Christians criticize Atheists for not believing in God, they do the same to us. I am Catholic myself, but I think it's God's choice on to choose a person's religion. Some Atheists just don't believe in religion, but don't criticize others for believing, but then get tired of the believers who try to change them so much. I've seen that happen to a friend of mine multiple times.
Whether God exists or not, religion is just something to give you hope and faith and to keep you going when things look bad. Atheists can be two things: someone who feels that they don't need hope or faith and just want to go on living life as it is, OR someone who has had a bad life, tried faith, but had no success, so they blame religion for not 'helping' them.
I'm not saying that all Atheists are bad though. I'm just talking about the Atheists that legendster is questioning about - the ones who hate religion. To the ones who simply just don't believe in religion, but doesn't hate it either, I respect your beliefs.