I agree with a lot of what you write and your general sentiment towards demanding quality and high standards, but this is nonsense.
Totally bizarre nonsense, at that.
The bar for "allowed to practice medicine" for the USMLE is a passing score. Which IIRC is somewhere in the 170s for each step of the USMLE. Also IIRC the mean is around 210.
The passing scores, in my time, used to be around 188. Now they are 192 for Step 1 and 209(!) for Step 2 CK. So the NBME felt exactly the same as I did, and raised the bar significantly for Step 2. For Step 3 it's still 190.
You're saying that anyone with a couple scores below the mean shouldn't practice medicine? Really? You think half (or nearly half) of US allopathic medical school graduates are missing the fundamentals to practice medicine? That they have low IQs?
No offense, but somebody who scores 199/199 on Steps 1 and 2 CK does not have a huge amount of knowledge. That's only about 60% of questions answered correctly. And Step 2 CK is very much a matter of logic, too, not only of pure knowledge, so IQ does matter. Also, the national mean for Step 1 is 227, with a SD of 22, meaning that 84% of the test-takers will have a score higher than 205. For Step 2 CK, the numbers are 238, and 19, meaning that 97.5% of the test-takers are above 200.
Anyway, the idea was that people who have trouble covering large amounts of material for these exams end up practicing IM, FP, Peds and other primary care specialties, where they will need an even more encyclopedic knowledge. This while the high scorers end up in many procedural "non-brainer" specialties. Isn't it ironic?
Nonsense.
You should back up even further. The purpose of the USMLE has always been (very explicitly I might add) to verify, via a passing score, a minimum level of knowledge to practice medicine. It was specifically not designed or intended to be used as an aptitude test to stratify test-takers. That residency programs would use the scores in this manner was obviously unavoidable, but that's not the purpose of the exam.
Sorry, I will not back up. See why above. Not only that, but I think that the USMLE, and similar anonymous objective national exams, should become the standard of admission to residency/fellowship etc. Not interviews, "research", CV, and other BS that was invented to make sure that certain people will get accepted in certain places. See the South Korean, the Chinese or the Soviet model. It's not surprising that all those systems excel(led) at science- and knowledge-based jobs.