You have to keep in mind that med school and the equivalent of premed in germany is completely free. Of course that does not make up for the pay difference completely but it changes the perspective quite a bit imo, since med school in the US is extremely expensive. Additionally I could totally see doctors being ok with less pay for the trade off of living in a more fair system. Coincidentally I know one expat here that specifically does not want to return to the US to become a doctor there for that very reason. She specifically does not want to move back because she feels the healthcare system in the US is unfair and she would be profiting off of that system.