Its unfortunate but science isn't about making people happy and a theory saying god was an ape would leave every one unhappy.

The religous were extremely unhappy (to say the least) to learn humans and apes evolved from the same ancestor, how angry do you think they would be if we suggest that god was an ape.

And science would never consider it cause it lacks proof, and would require what could be defined as 'GOD' if god was a physical entity.