Why, because he says that the brain of every man, women, and child will have artificial enhancements that will connect to the cloud and give everyone direct access to every piece of knowledge obtained throughout history. By the 2040’s, the human brain will largely no longer be a biological system at all, but an artificial one.
First off, the “what could possibly go wrong” factor here is immense, imagine if a rogue entity hacked into that cloud and was able to literally control the minds of every person on the planet (fighting back in turn will not be an option, because no one will know how to do that). I could get hacking the brain to make learning and memory abilities a lot more powerful and a lot more efficient (so overall intelligence and man’s ability to develop new technology gets a vast increase that way), but having everyone on a mind-link akin to the Borg in Star Trek or the Matrix Trilogy, while potentially leading to things like unlocking the secrets of interstellar travel in a matter of minutes, might just be a risk too big to take.
First we accessed the internet via the computer, then sometimes soon the internet becomes the computer, then the internet comes for us (and maybe our pets), and then we see a world where people could do anything and do it in any form they want (be it a dog, an dinosaur, a Dragon, an amorphous blob, whatever), is this something we would actually want to see happen?