In other words, unless it shows what the student "gets" out of the experience when done, they are selling dreams.
A money-based measurement is also heavily canted toward the "old money" set and their legacy admissions to their alma maters.
Money isn't everything. And often it isn't even accurate at measuring how well a school equips students to make it on their own.
Medical school costs (and the insurance load to practice medicine) are already tipping the scales against GPs (low return on educational investment), and many medical students already know this. The real looming healthcare crises will be when the margins on being a general practioneer sinks below the educational investment cost, and all we are left with are specialists.
As far as investment return on the cost of college education goes, earnings would be a useful metric, especially when one has to finance the education with student loans that have fixed rates of repayment. It is the most universally applicable metric, and although it may not make everybody's world go around, it does keep things from coming to a grinding halt (apart from coercion and intimidation).
In any case, I doubt the college U.S. News college ranking is the largest signal to where most incoming freshman apply.
The effect on GPs you describe is already driving a health care crisis in the US. We may be left with an overhang of specialists who will surely argue their education should not become a "stranded asset."
If anything, I am most critical of a single ranking that is supposed to tell me how good something is crafted from within the community that is being ranked.