They don't, physicians are close to gender parity. What you see is that Physicians used to skew male a long time ago, but that isn't the case any more in younger generations.
And Physicians isn't about people, Physicians is about seeing people as things you can fix, so it tickles both the "people" and the "thing" aspects at the same time, which would explain why gender ratio is about equal.
If you remove the "things" aspect from physicians you are left with nurse, which skews extremely female.
"Countries with greater gender equality see a smaller proportion of women taking degrees in science, technology, engineering and mathematics (STEM), a new study has found.
Dubbed the “gender equality paradox”, the research found that countries such as Albania and Algeria have a greater percentage of women amongst their STEM graduates than countries lauded for their high levels of gender equality, such as Finland, Norway and Sweden.
The researchers, from Leeds Beckett University and the University of Missouri, believe this might be because countries with less gender equality often have little welfare support, making the choice of a relatively high-paid STEM career more attractive."
Basically finding that specialities with less patient contact have a higher proportion of male doctors.
Though I suspect there probably is more going on with nursing than differences in interest in people.
Why is it different when a woman is taking vitals and walking through a diagnostic checklist than when a man is doing it? Is there something special about being a women that makes the better at drawing blood or placing IVs?