Everyone who believes in God seems to think he's great. Everyone who doubts his existence thinks he's evil. Someone must be biased, and I understand why some would think it's the atheists. After all, if they don't believe in God, why do they bother going around saying such hateful things about him? Hold that thought, and let's try a thought experiment.
Imagine a trial. Before the trial even begins, the judge announces that each jury member will be awarded one million dollars, no strings attached, if they judge the defendant not guilty. Whereas, if the jury finds the defendant guilty, they'll all be spending some time in the torture chamber downstairs.
In your wildest dreams, can you imagine that this would be a fair trial?
As you may have guessed, the defendant is Jehovah. So is the judge. So is the executioner, the security guards, and pretty much everyone in the room except for the jury. We, the jury, the human race, are being strongly encouraged to judge the defendant positively. If God is on trial, it would be an understatement to say that Christians are a tainted jury.
Still think it's the atheists who are biased? We don't even believe in hell. We think it's all fiction. We are not the ones living in fear of being sent to hell or deprived of heaven if we judge God negatively.
Neither do we have any reason not to judge him positively. For instance, I would say that Santa Claus is a nice guy. He gives out free presents every year. It's a little bit communist, but he only gives to children who are nice, so at least he's incentivizing. Overall, I'd say Santa is a benevolent character, but sadly non-existent. There's no reason I wouldn't judge Jehovah similarly if he were depicted as a benevolent character in the Bible. In fact, trash-talking an obviously benevolent god-character would only hurt my case and my credibility as an atheist.
So why do I judge the Christian god so harshly? Because he is evil. And because a significant portion of the population constantly hold him up as a paragon of morality and demand unquestioning obedience to him. I don't fear any gods or hells, but I do fear legislation based on the whims of a villainous fictional character.
Now imagine that 75% of the USA believes in Voldemort. They see him as the hero in the story of Harry Potter. They call him a god of love, and promote blind obedience to him. They put his name on the currency in your pocket, force your children to either pledge allegiance to him or stand out in the hall, and vote for all manner of legislation inspired by his twisted moral code. If you object to any of these things, they cry persecution while ironically standing atop a pedestal of privilege, supported by an overwhelming majority of Voldemort-worshipping politicians and judges. "This is a Voldian nation," they say. "It was founded on Voldian principles. Get used to it, or get out."
If you can imagine that, you might just begin to understand why atheists in America have been putting up so much fuss.
“The God of the Old Testament is arguably the most unpleasant character in all fiction: jealous and proud of it; a petty, unjust, unforgiving control-freak; a vindictive, bloodthirsty ethnic cleanser; a misogynistic, homophobic, racist, infanticidal, genocidal, filicidal, pestilential, megalomaniacal, sadomasochistic, capriciously malevolent bully.” -- Richard Dawkins, The God Delusion