AI risks

This, from Tyler Cowen, has been doing the rounds: he tells us not to worry about artificial intelligence. Scott Alexander takes issue with it here, Noah Smith broadly agrees with it here (albeit, in typical Smith fashion, he disagrees with the most obviously correct bit of it), Zvi disagrees at really quite some length here and then Tyler replies to Scott here. No doubt the usual suspects have been chipping in elsewhere as well. So I don't feel too bad about adding my two bytes. 

In short, I'm not worried about AI. Perhaps I should be, but I shall try to explain why I'm not.