I must confess I have a personal vendetta against Yudkowsky and his cult. I studied computer science in college. As an undergrad, I worked as an AI research assistant. I develop software for a living. This is my garden the LessWrong crowd is trampling.
Some people want wondrous machine gods that are better than people that will take care of them, and being reductionist about living human beings (or other animals for that matter) makes the wondrous machine gods seem that much closer to reality.