I hope SI will agree that the FAQ answer you linked is inadequate

As Randaly notes, an FAQ of short answers to common questions is the wrong place to look for in-depth analysis and detailed self-skepticism! Also, the FAQ links directly to papers that do respond in some detail to the objections mentioned.

Another point to make is that SI has enough of a culture of self-skepticism that its current mission (something like "put off the singularity until we can make it go well") is nearly the opposite of its original mission ("make the singularity happen as quickly as possible"). The story of that transition is here.