It seems to me that no set of preferences that can be specified very simply without appeal to human-level concepts is going to be close enough to what we call "good" to deserve that name.

a consequentialist deity is fully entitled to destroy two cities to save 10

I entirely agree, but I don't see how this makes a substantial fraction of the arguments for atheism unravel; in particular, most thoughtful statements of the argument from evil say not "bad things happen, therefore no god" but "bad things happen without any sign that they are necessary to enable outweighing gains, therefore probably no god".