Spider,
Pretty good analysis. Puts me in mind of a story.
When I ran in college, we raced tons, especially in xc. We'd have somewhere on the order of 12-17 meets a year. Usually we had one, or even two, in the middle of the week and one on Saturday. We loved the mid-week meets, not just because they got us out of a couple days of getting hammered with intervals at practice, but because they were often away meets and gave us a legitimate reason not to be in class. One of the highlights of every early September was cross referencing our meet schedule with our class schedules to see what classes we'd get to miss.
Not all thst many years later, after graduating, I went to watch one of my old school's xc meets. I'd noticed that they'd been running maybe 7-8 meets a year, roughly half of what we'd done. I asked the coach why the big reduction and he told me that one of the main reasons was that "these kids just don't like missing classes."
There was once a great article in the old "Runner" magazine about "running bums," people whose running ability was anywhere from somewhat above average to considerably less than average who had chucked careers and scraped to get by so that they could concentrate completely on their running.
All of that said, it's worth noting that there were also many, many, runners from that era who held down full time jobs and even supported families and who still trained seriously. My best running came when I worked full time as a high school teacher.