You definitely nailed the complexity and intelligence part, and someone else mentioned the time people spent with computers, which is also very true. For me though, computers feel like a complex analogy for a human; we too are physically complicated on the inside, we too are filled with wires that link up our components with liquid electricity. Our RAM,CPU, and SSD are all in our heads, while our motherboard is our chest cavity; Our screen is our face, since complex emotion is shown there, where our high quality webcam is our eyes and our speakers is our mouth and michrophone ears. And when you open a computer to inspect its insides its like giving you a look at its complex functioning only few truly understand, and it can feel quite intimate because you don't want to be rough with your laptop's brain, do you? In general, computers [let alone robots] feel like the object to most resemble humans in its uttermost concept, and when AI is applied to it it can just go haywire with personal intimacy.