My perception is that people, especially at that age, feel pressure to follow a track, and going to college is expected, and some majors are easy, and so they follow the path of least resistance.
My institution offers a seven-year combined BS/MD program. Graduate on time, get an MCAT score above the national mean and a decent GPA, and after 3 years you are automatically admitted to the institution's medical school. One requirement for admission into this program is an ACT score >= 32. Of this cohort, only 60 % made the cut.
60 % is low. This can't all be students that transferred out because the undergrad instruction is too awful or are otherwise incapable. I would put the blame squarely on the irrelevant curriculum and also would not hire anyone from that place because the level of instruction is just too low.