Higher education in this country needs an historian to tell us the organizational history of colleges and universities in their expansion, both as real estate enterprises and as they have found more subjects to confer degrees and certificates in. Perhaps the book has been written, but if so I've missed it. I see bits of the history in the newspapers, as Advisory Neighborhood Commissions push back against the expansion plans of the local schools. And I see it in the mail, when a local university advertises its Master of Interior Design program.
The physical expansion I suppose derives from the money that schools accumulate through their favored tax status, and from the need to use that money. The increase in the number of subjects seems to be driven by demand. Applicants for jobs suppose that a Master of x in y must be a positive value, for any values of x and y. Perhaps so; perhaps in the human resource offices the resumes get sorted into different pile. But the schools are out there scrapping to meet the demand.