Agh, not again. As far as Kurzweil theories are semi-crazy and border on beliefs, he is not forgetting about social learning. What you are forgetting is that these things could be done much more faster on a machine than on a human being, especially if we had a better grasp on how they happen. Especially considering they don't need to also develop a physical body. And some things that we learn when we are babies could be "built-in". Also, I don't believe that Kurzweil would say "We wouldn't deliberately build in any pathologies of any sort."
And to finish this rant, the idea is that this "improved social learning" would also be applied to humans, not only to AI, because it would be a really important tool. And that may be the main reason why we would develop something like that.