Premeds aren't required to take upper level bio, they do that to themselves.
Right, they do, but only because they are required to take something to fulfill 90 credits IN COLLEGE at an accredited U.S. university...If you read my post, I'm advocating for getting rid of that credit requirement (and making it a non-preference) for acceptance into medical school. Instead, students should be required to just do BCPM and a few extra classes (of course if they want they can still do 120). If you want to formalize the few classes so students don't just take scattered junk and are productive establish what I'm calling a "pre-med track". That track should consist of BCPM (about 40 credits) + a non-human-biology "proficiency" (20-70 credits). That proficiency can be computer science, statistics, music, literature, economics, engineering, foreign language, etc all of which have value and can make someone a more critical thinking, diverse, and balanced physician. (Also, you'll get less students whining that they took harder tracks within the same university because using this model, BCPM GPA is weighted more heavily).
This will shave a year off for the traditional student and let those who carry credits from high school to shave off even more. The only drawback is that this cuts out the traditional liberal arts education that universities require where you're required to take 2 social sciences courses, 2 humanities, etc. I think, however, that those classes (where you do things like analyze Romantic literature) are best taught in high school where you can actually have meaningful discussions as opposed to a 40-200 student lectures (my experience at a large mid-tier research university vs. an all-IB high school).
If students really like the liberal arts education, they can choose to go to a liberal arts college and do that. I think large universities should start offering these opportunities to pre-meds and medical schools should start accepting them. Also, high schools need to beef up their curriculum in that ALL students are proficient in some intro BCPM, lit, history, and foreign language and many schools with lots of IB/AP classes have.
This can literally shave off 3 years of the medical school curriculum for some without compromising any safety or quality of training (which really comes in residency) whatsoever. The ones who argue that some extra undergrad classes make one a more qualified physician really are just kidding themselves. I recognize that this is already in place with BS/MD programs. These programs are pretty competitive though and I wasn't able to get into one even though I could have skipped two years of college. In this era where student loan debt is becoming a bigger issue, implementing something like this should be a serious consideration.
Some others may argue that there's an issue of maturity and a lot of younger applicants who struggle on the application trail can attest to that mindset being prevalent in admissions. I really don't know why though. Have we done experiments and collected any data that support the notion that you need to be at least 20 before you enter medical school? I'm not saying that the maturity gap isn't a thing, because I can literally see the spectrum in our 19 y.o's vs 23 y.o's vs 27 y.o's, but I think that as long as the student can manage the rigors and learn professionalism, they should be allowed in. Initially, you may see failures and other disasters...but eventually the word will trickle down and only those ready for the rigor will put themselves through this.