Terminator isn't the scenario Elon and Steve are talking about. But it's a model that still fits their concerns.
Automation applies economic coercion to the laboring humans to serve the interests of the automation. For instance, Watson is an AI technology that is being positioned to lay off a lot of people in phone call centers and taking orders for drive-up windows. Actually, Watson is being aimed at a lot of jobs. All those displaced workers cascade to flood the job market. Maybe they get some training to compete for trades such as electricians, plumbers, and taxi cab drivers. With so many available applicants, the wages for those jobs go down. The economy for the middle class tanks. With people desperate to feed their families, do you think they'll really scrutinize that ad looking for workers to build the drone factory? The drones that are intended to fire missiles at the 'terrorists'?
AI is a wealth concentrator. That's what Elon Musk and Steve Wozniak are talking about. It is increasingly developing the capacity to eliminate millions of blue collar jobs in order to enrich people with white collars. The Terminator series is a colorful depiction of this process.