Most students come to business school for a handful of reasons, (roughly in order of priority):

1) To break into new industries or functional specialities
2) To punch their ticket in order to get a promotion
3) To make connections
4) To re-brand their resumes with a better educational institution
5) To actually learn something
6) For a company sponsored “vacation” (esp. consultants & bankers)
7) To ride out a lousy job market

In almost all cases, the student anticipates compensation increases to make the investment worthwhile. A general curriculum addresses all but the first item, and elective courses can enable learning a new field.

MBA students come with a wide range of expertise and the first year core curriculum is a way to ensure everyone has a grounding in the basics. Also, many of the students that become investment bankers and consultants upon graduation eventually enter and lead operating companies. Those in private equity and VC shops still need to be able to think like managers. While the Master of Finance may be a better course of study for the functional specialist, the MBA will retain its appeal as a generalist degree.