Why? Maybe we are using the word "perspective" differently. I use it to mean a particular lens to look at the world, there are biologists, economists, physicists perspectivies among others. So, a inter-subjective perspective on pain/pleasure could, for the AI, be: "Something that animals dislike/like". A chemical perspective could be "The release of certain neurotransmitters". A personal perspective could be "Something which I would not like/like to experience". I don't see why an AI is hindered from having perspectives that aren't directly coded with "good/bad according to my preferences".