I do apologize for not reading 192 pages before responding

I'm not sure you needed to. You just needed to read this bit of Roko's excerpt properly:

In the previous chapter we concluded, in spite of common sense, that moral realism is false. This raises an important question: How is it that so many people are mistaken about the nature of morality?

The subsequent excerpts are aimed at the second purpose; not the first. (At least until Roko inteprets them in support of first at the end of the OP; but in context it seems reasonable to think they buttress the case against realism here, even if they don't provide a stand-alone justification for it.)