In short, the iPhone Way to simplicity is a combination of limitations and control, and both of these tenants are completely opposite to what we have known about personal computing.
It is my belief that Steve Jobs views the iPad as an implementation of the iPhone Way to personal computing, and because that the iPhone Way is completely opposite to how we have always thought of personal computing, there are a lot of negative reviews of the iPad. You see arguments like “the iPad does not multitask (run mulitiple programs at the same time) so it is not a real computer,” or “the iPad does not have any USB ports to plug in hardware peripherals, so it is not a real computer.” I think both of these intentional design limitations were made to make the iPad simpler to use, because, who is to say that our definition of personal computing today will be the same definition ten years from now.