Regarding students choosing pre-professional majors, note that some liberal arts majors, like math and economics, can be chosen for pre-professional reasons (e.g. aiming for quantitative finance and the like). Also, some of the super-selective schools are favored in recruiting by consulting and Wall Street, but with less emphasis on the student’s major, so the incentive to choose explicitly pre-professional majors may be less there. Also, most of the super-selective schools have scions of wealth (receiving no financial aid) for about half of their students, with relatively few from middle and lower income families (the latter aspect is shared by some public flagships like Michigan and Virginia), so the students may have less of an immediate need to have a job at graduation.