Because its not a matter of you can't believe its a matter of you won't believe. Because then you will be accountable for what you do. And you can't have that, so you deny.
Pop quiz: what is the 9th commandment?
I don't get offended by much. But this^ is one of the few things that offends me. What do you know about velkyn, me or any other atheist that makes you think you can make this statement? Are you a mind reader? Have you met velkyn (or me or any other atheist)? Have you seen a survey of atheists where they say that is why they don't believe in gods? Have you observed velkyn (or me or any other atheist) behaving in such a way as to make you think accountability is a problem for us? Is velkyn (or me or any other atheist) running amok more than any one else in society?
You see, jake, I hear that same line a lot from xians. And I look at my life and wonder how that could possibly be the case. I am married. I don't cheat on my wife. I drink only in moderation. I don't do drugs. I don't steal. I haven't killed anyone. I don't attend wild sex parties. I have a steady job. I have no problem accounting for myself. So for me, no accountability is of no benefit.
From what I know of velkyn, she is in more or less the same boat. So a deficit of accountability would be useless to her as well.
In fact, most of the people I know are either atheists or only marginally religious. None of them behave in a way that would be shameful. IF there was a god and that god was the god described by xians, the only basis for any of them going to hell would be they don't believe in a god.
So I am perplexed by your stupid accusation. Tell me, jake, just why would you make such a bold claim? The best answer I can come up with is you are a bigot, repeating the bigoted slander of your bigoted church.
The answer to the quiz, jake: thou shalt not bear false witness. Why does lying seem to be part and parcel of being a xian these days?