I wonder how the non-Americans here perceive all of this. While I'm sure there are some people who motivate themselves to become doctors with visions of Ferraris and mansions dancing in their heads, I doubt it's the primary driving force among the vast majority of them throughout the world.
I don't think anyone would begrudge them a comfortable living though. However, the same could also be said for schoolteachers, but we just don't value education quite as highly in the US.