For me, it was all about the better job prospects. When I was studying 2nd year undergraduate physics, I could find no jobs related to my field of study. This really put me off, and I lost all motivation to work hard in my studies (and I had been an A student); in those days, my favorite thing to say was how hard physics was and how it was "all for nothing, all for sh**". It's just one of those hard facts of life that you are 100 times more likely to find employment with a B.Sc. in an applied field like EE than say a pure field like physics (at least that's how it works here in Canada). There is, of course, always graduate school, but my rationale was that I'd spent the last 12+ years in school and wanted to get out of it and not just get another degree that you "can do anything with" (not unlike a HS diploma).
Yes, in fact I love thinking about such questions, but I'd much rather do it from the comfort of my relatively secure middle class life than that of a post doc struggling for tenure, or researcher worried about government cuts, and c. I can pick up a book anytime to find out more about such questions, but to convince someone that I am employable requires a practical degree I'm afraid.