I don't think we disagree. But it's likely that most people who end up in a Ph.D. program in Medieval Studies don't have many passions that are marketable: there's a lot of self-selection involved, and if the main subject of the article was also passionate in, say, EECS, I think it's a fairly good bet she would have chosen it. And passions in Medieval Studies are likely correlated with similarly un-marketable passions.

Though, maybe not. I could totally see someone being really interested in the structures of everyday life of medieval peasantry. Seems worthless, but you could totally parlay that into a profitable business doing furniture making or even green/natural/traditional housing.