Man, observing the shere complexity of his environment, made a classic assumption...that whatever causes that complexity must be even more complex.
I am with you so far.
This assumption has followed man down thru history as one form of theism or another.
Not being a theist myself I disagree with your assumption. Theism is and can be innate, since ancient man and ancient time, man has in every culture prophesed without teachings, that there is a god or goddess or ultimate force. History proves your assumption unjustifiable.
Sometimes it is wise to question these assumptions themselves
Likewise, sometimes I question how philosophy ended up being science? It isn`t science. It has a branch called science.
Random isn`t logical, random is unverifiable
I must go now, but I will return to address the rest of your posting whynot, as it is valid in some ways and invalid in others, but shows the differences in the way I see it to the way you see it, and the will to make this a productive not a deductive difference.