If they don't think God exists, why do they seem to hate Him so much?

Read this:

I have been a Catholic for a long time and I have never heard the words "atheism" or "atheist" ever mentioned in church. An atheist prior to converting to Catholicism, I can assure you that that community is obsessed with the Church and incapable of discussing anything but the most recent reason for hating us. They never talk about the wonders and glories of atheism. They never raise virtuous atheists as models for themselves and their children. They never organize themselves to help the unfortunate. Frankly, after a couple of years, I simply couldn't take it anymore. I left atheism behind because it was snarky, sniping and moribund, revelling in its bitterness and denial. It is amazing that anyone survives the wholesale rejection of logic and reality, never mind hope, as they cherrypick data to uphold their opinions. 

Then look back at this. (It's the atheism your atheism could smell like.)