however P(evolution | moral God) would be rather low.

ie, think about all the nasty stuff that had to happen to, well, give rise to all the currently existent beings. Evolution is a nasty process. A god that is sufficiently intelligent and powerful that it COULD have engineered the species it wanted right from the start, rather than just setting stuff in motion and waiting for something interesting to evolve, allowing all that suffering to happen in the process, well... that would seem to exclude such a being from having anything resembling human morality, right? So when taking into account the often associated "god is good" claim, well, the whole thing completely implodes, no?