It is not the technical competence of the boss that is the determining factor, it is the competence at managing technical people. Technical competence of their own can help this, though it doesn't always, But it's not mandatory. I have one boss (out of three) who can reliably turn a computer on and off without printed notes (with pictures), and he has very little idea what I do. But they're good people managers. They recognize that they know basically nothing of what I do, and leave me alone to do it. They know what they want - network up and running, computers not overly slow, various new toys their friends have, and they know how to tell whether or not they're getting it. Everything else they leave to me, and when I tell them "that's not going to work" or "it's going to cost this much, and you don't want to spend that much," they trust my judgment because they know I know more about my job than they do. I've been on the same job for over 20 years, and still look forward to going to work every morning.
Managing people is a specific skillset, and not an easy one to master. And it's an important one, that computer geeks wrongly dismiss in much the same way that MBAs wrongly dismiss technical skillsets. It's a popular mistake that managers have to (pretend to) be able to do every job in their department, because MBAs are taught that. But it just isn't true.