She's been an adjunct for years, there are virtually no tenure-track positions available, and the ones that are have 100 applicants as well qualified as she. And that's a STEM field.
I remember a Doonesbury comic from 40-odd years ago where one of the professors at Walden was grumbling about his salary, and threatening to move to the private sector to be paid what he was worth. The punch line? "You're a Latin professor!" Let's not pretend that many in the liberal arts would be able to market themselves in the private sector: PhDs driving cabs and serving coffee are a byword.
But yeah, the amount of time and effort spent getting the degree and doing the research even to be eligible for a tenure-track position takes considerably more opportunity cost than getting your MBA ticket punched and shmoozing your way into an executive position in business (to say nothing of government). Back in my grad school days, the profs went on strike, and for the most part they were being paid modestly, albeit comfortably. Even then, the pressure was mounting; he who could get the grants was the fair-haired boy, and teaching was only secondary to publishing and researching. That is the reason why the "product" of universities has been shifting for so long, from educating people to getting the bucks from government and industry. The result has been a proliferation of community colleges, where there is more of an emphasis on actually teaching, and where conditions for staff are at least as appalling, if not more so, than in four-year institutions.
Even thirty-odd years ago, these trends could be seen, and my advisor in grad school (I was in the history program, as it happens) told me my best shot would be to get into administration. (Largely because I had a rep as a hard-ass, but that's another story) Smart man, that prof.
-- Mal