I'm sure that you and others enjoy philosophical arguments and big words and such, but I didn't give atheism that much thought when I concluded that there is no god. I was in the sixth grade, and being taught about Greek myths, and how interesting, yet false they were. Then I was going to church on Sunday mornings and being told the same sorts of stories and being told how wonderful and true they were. And I'm no dummy.
To me, that was far simpler than the heady stuff. People long ago claimed that there was a god. He was said to do great and wonderful things, and everyone (in that region and in that group) was told he loved them. And sinning was taboo, but inevitable, but hey, if you know the password, no biggie. But that was long ago, and he hasn't done anything to cause believers to put out an amended version of the bible, updated with the latest and greatest. Hence it appears to me, at every level, to be a story. One that applied to peoples lives thousands of years ago, and still applies to some lives now, but in all cases it has been, and remains, a myth.
Being as the religious can do nothing but claim they "know" him or otherwise sense his reality while the rest of us stand around saying WTF every time such claims are made, I have no reason to think otherwise.
By the way, if you and I are in a room where you claim you see a table and I don't, I merely need to walk right through the thing you see to prove it isn't there, or bump into it to prove to myself that I am wrong. Most of us are blessed with multiple sensory input devices and claims outside of the realm of god are generally much easier to deal with. Maybe not string theory, but nobody is telling me how to act or shooting at me because we disagree about that one.
A non-existent god can't co anything, but believers are adept at moving goal posts and otherwise changing the evidential requirements every time one of their "proofs" falls apart or at least appears ineffective. And the variety of excuses that christians (in this case) have come up with in part explains why there are thousands and thousands of different denominations.
Truth doesn't need that many varieties.
I don't need to know there is not a god. I only need to know that claims of such a being are so flawed that I don't have to give them any weight.