The people who are gatekeepers to master’s degrees have naturally two conflicting motivations: to maintain standards of quality and success in their institution and to have money and enrollment.
As I’ve researched various educational tracks for people on this forum, I’ve learned some things. (I don’t always like them, but I accept the reality of them.) Accepted preparation for graduate programs often is a set of prerequisites which is far less than doing the whole major. And sometimes in these cases the prerequisites can be taken after admission to the program. An example is a program in brewery science or some similar thing at UC Davis - it may be that for odd areas of study a program won’t attract enough graduate students without that flexibility.
Something that comes into play with (the increasingly popular - http://www.usnews.com/education/online-education/articles/2013/01/08/online-course-enrollment-climbs-for-10th-straight-year) online degrees is a lowering of visibility of student weakness/failure. This, the practical ability to handle much larger numbers of students, and the far lesser cost of educating people online naturally function to reduce the drive for student quality.
http://www.mba-options.com/mba-admission-requirements.html suggests entrance to an MBA program after a bachelor’s degree in anything is highly doable even without resorting to an online degree. From http://catalog.ucdavis.edu/gsm.html: “A bachelor’s degree and a strong interest in professional management are prerequisites for admission to the Graduate School of Management. The school seeks students from diverse professional and academic backgrounds and does not limit its consideration to applicants from any particular category of majors.” I see that courses in accounting are available within that program.