You have to complete a number of prerequisites to be considered, never mind accepted, into a medical school. For engineering the barrier is much much lower, hence the higher dropout rate.
However, with supply management of physicians, comes responsibility to ensure reliabile supply to replenish ranks to avoid surprises, and thus all efforts are made to ensure that students can pass. You simply can't have 70% fewer graduates one year, and 170% next.
"With an admit rate of 7%, it is easy to understand why the Johns Hopkins School of Medicine is sometimes viewed from the outside as highly competitive."
"Massachusetts Institute of Technology/Acceptance rate - 7.3%"
If you have good memory, and not a total dolt, you can be a physician. Analytic ability is a tertiary concern.