A lot of atheists are hateful because they believe in God and they hate God. They don't hate the Tooth Fairy and they don't hate Santa Claus but they hate God who they claim doesn't exist. They tend to be people who don't like how God runs the universe that he himself created. Or they love evil and don't want to be accountable to a supreme being.

The good thing is that so many of them are so obnoxious that they fail in spreading their religion. Atheism is a religion because it answers the these questions: how did we get here (we evolved from pond scum); what happens when we die (we rot); what's the meaning of life (there is none.)