I'll try, although I don't have any special insights, I don't think it's mysterious. From goodside's comment: "I majored in CS." From yours: "CS and physics maajor". I probably don't have to tell you that there's tremendous demand for so-called STEM majors. I don't know about your friends' majors, but these are really both "isolated, non-representative examples".
I think there are plenty of people going through what this 29-yo is going through, and part of that might be because they have degrees in things like English, Art history, Philosophy, etc, and have little or no concrete idea of how to apply this degree in the real world. Part of it is also because there is little support for developing skills outside your narrow major in many colleges and universities, and there's this drift between what many students expect from school (prepare to get a job) and what the schools deliver, which is more abstract. Plus many new grads don't know much more about how to go about finding a job than just pumping out resumes, because that's what they're told to do by (some) "career centers" and counselors on campus.