There are no jobs that Americans are unwilling to do. Only salaries at which they are unwilling to do them. Cut a doctor’s compensation to $90,000 a year, and nobody will go to medical school. Cut an engineer’s compensation to $35,000 a year, and nobody will complete an engineering degree.
Americans are overqualified for these jobs. (By $30K)...
Oh, and just as an aside, an American can't get a job for $50K.
It's the same sort of reasoning someone else used today:
Hmm, I probably wouldn’t hire an MBA to do desktop support. You might leave after a few months and I’d have to start my search all over again.