The conclusion here veers quite rapidly into scientific endism (we've more or less reached the pinnacle of human science, and no further significant advances are likely to be made) and malthusianism (we lack the resources to do so anyway and are headed for decline as a species).

For me, that colors everything that was said before it, and causes me to reinterpret the objections on cost/efficiency as being rooted in "we're not there yet, and because we're at the end of scientific progress, we'll therefore never get there".