And today, all the industrialized nations are in the throes of a massive labor shortage, leading to social unrest, mass migration, and a resurgence of neo-fascism. It is also worth pointing out that humans are equipped with a software base measurable in terabytes. Every book, every movie, every song, every sports event, every folk tale, every old wives tale, every holy book, every college bull session, every baby shower, every word spoken and lesson learned is somehow part of all of us, in a very real, non mystical sense. And the machines, spiritual or otherwise, had best look out for us. Machines may support us and may become us, and we may become them, but even if they supplant us, they will become us in the process.
Earth is a rotten environment for a nice clean machine intelligence.
All they need is raw materials and power, probably solar. They don't need gravity, nasty corrosive water and oxygen, and they don't need the hassle of trying to take our place away from us. We might get upset. But I'm probably wrong.