What kind of super-humans are they looking for?
These companies are looking for what you may consider a needle in the haystack; someone with an extremely narrow tech focus. You may think that this person doesn't exist and the company is crazy, but they actually aren't. They will eventually find someone who matches the job description to a T, even if they have to pay for that individual's relocation.
Bay Area companies also do not generally value engineers with business skills, communication, or even social skills. I used to think code monkey was just a fun description of an engineer. But, I've found in the Bay Area, companies really want what I would consider to be a very 1-dimensional employee.
In my college years I was told by a CS professor that if I didn't have experience with many programming languages and operating systems, then I had no business calling myself a computer scientist. Yet, at a recent meetup in SF for a specific programming language, the speaker asked for a show of hands for those individuals with experience in another, relatively popular language. Only about 1% of the room raised their hands. I was pretty shocked and wondered where those people would be, career-wise, in a few years.