HN in general is a pretty specialized group of people that skews heavily towards engineering and technical jobs. And those aren't the other jobs out there.
Just as the GP could have been a journalist, copywriter, etc... they just as easily could have been a doctor, or a lawyer, or gotten an MBA.
No, he/she really couldn't have. You just listed two heavily regulated professions where not having the right degree means complete disqualification from holding a job. There is no way for GP to be a doctor or a lawyer without going to medical school, or law school, respectively.
At least here in the tech industry you're not legally mandated to have the right degree for the job.
This seems to support the notion that one ought to look at a degree's employment ramifications before jumping into one.
That's what I am trying to say in another thread here. You picked a major, now pick a job which is backed up by it, or augment your education on your own and grab the job you want. One can't just claim "education is more than training for jobs", "I am well rounded" and grab a totally unrelated job.