Someone once said: "An atheist can't find God for the same reason a thief can't find a policeman". I think that pretty well describes the primary cause for atheism. Of course, spiritual ignorance would be a close second.
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So what.  Someone also mistakenly said, "there are no atheists in foxholes."  And then thousands of atheists who are soldiers came out and made a mockery of "someone said".
 
What you should have said is, "I think that pretty well describes what I believe to be the primary cause for atheism."
 
And then the statement would have been unarguable.  You are wrong, deluded and mistaken, but what you believe is what you believe.
 
Good luck with that.