...because 20wk EGA pregnant females never need their hands reconstructed?. Honestly, why does the med student who KNOWS they want to be a hand surgeon spend all of that time learning which antibodies can cross the placental barrier? Is it good to know? In an ideal world absolutely, but pragmatically, it's antiquated.
...because it's rare for medical students to not change their minds, especially during 3rd or 4th year rotations?
...because there's a certain level of knowledge that society and general medical practice expects out of all physicians?