I find it hard to believe that people still ask this question. Without wishing to be disparaging, it's a stupid question. It would be very stupid of me to ask you what pushes you to not believe in Odin or Atet. In truth, there are no reasons I can think of why you should believe in either of these gods, anymore than there are for atheists to believe that yours exists.
The exact reason they don't believe is the same one you have for not believing in all the other gods. That is not only enough reason to hold the position, it is more than enough, as you well know since you're in the same position.
Belief in gods are taught to us from an early age and they are re-enforced by society as a whole on a daily basis. Anyone who doesn't reflect on the issue will more than likely continue to believe it, at least passively. Only those who "think about it" can possibly come to the conclusion that it's not true. So yes, we have thought about it, a great deal and comprehensively, and that's why we don't believe it.
I have no idea what you mean by "did they balance things first"?. The question is perfectly balanced because there's a dearth of evidence in support of the claim. We should only believe it if there's a positive bias, tipping the scales in favour of the claim.