Religion is a poor source of morality

[Edwardo Piet]

Although I enjoyed the Moral Landscape very much, I found it somewhat lacking for the very reason that he doesn't offer much in the way of a defense for the ontological status of objective moral values.

Then you missed the point:

As philosopher John Searle once pointed out, there are two very different senses of the terms “objective” and “subjective”. The first sense relates to how we know (i.e., epistemology), the second to what there is to know (i.e., ontology). When we say that we are reasoning or speaking “objectively”, we generally mean that we are free of obvious bias, open to counterarguments, cognizant of the relevant facts, and so on. This to make a claim about how we are thinking. In this sense, there is no impediment to our studying the subjective (I.e. first-person) facts “objectively. (Harris, 2010, p. 29)

Source: https://zaknafein81.wordpress.com/2013/0...jectivity/

His point is never to ground objective moral values ontologically, that would be ridiculous (That is what William Lame Craig repeatedly bangs on about as a misrepresentation of Sam's position). 

His point is to scientifically measure subjective values objectively in an epistemic way.

To me, it makes little sense to claim that there are objective facts to be known about the differences between good and evil if you do not first acknowledge that good and evil are states which exist independent of one's subjective appraisal of those differences, much like the necessary truth that 2+2=4 regardless if a person has learned arithmetic.

But of course if good and evil exists at all it is not seperate subjectively. For good and evil boils down to well being and the outside world that has no affect on well being cannot be deemed good and evil at all.

Of course good and evil can't exist separately ontologically from us, that would be as ridiculous as claiming there was a God.