The worst part of HZD's apocalypse scenario isn't that we developed an AI so smart that it could kill us. It's that we developed a system too dumb to realize that it was killing us (and ultimately itself).
I mean honestly, it would have been better if the Hartz-Timor Swarm had a SHODAN level of consciousness, because then it would realize how dumb its actions were. Yeah lets eat all the food so there is nothing left, and then exist in limbo for the rest of eternity. What kind of consciousness would be fine with what is essentially oblivion? It didn't even have a backup plan for when there was no fuel left. If it was smart it could have switched to solar power, or invent a fuel source that was infinite for what it needed. Lets say it decided biofuel was the only answer. Well why are you killing everything as quickly as possible? It would be smarter to start rounding up docile humans and building fuel farms to eventually be converted to biofuel. It's a hellish image, but that would at least hint that the Swarm has some idea of self interest.
The Faro Plague seemed content to simply sit in stasis on the barren planet for eternity after all life was gone. I'm pretty sure even Skynet had plans after it wiped out humanity, the Swarm was just gonna sleep after eating the biggest buffet of all time.
The Swarm was too dumb to be considered a true AI, all it could do was Eat, Fight, and Reproduce. Sadly that is probably what also makes it the most poetic sort of apocalypse for mankind. The Machine that killed us basically did it by being better at our most base aspects than us (eating/killing/fucking), and being dumb as a brick while doing it. It's basically the perfect doomsday scenario for those afraid of what current corporations are doing (killing the planet for short term profit).
EDIT: Should say, since some are getting confused. I'm not talking about HADES, I'm talking about the Faro Plague.