I got paid even less (around negative $40k) to spend every waking hour 4th year of college to complete coursework, do varsity athletics, search for a job, and do an honors thesis. But these were investments in human capital.
I'm not sure I understand your point. They have already gone through 8 years of school which they definitely didn't get for free. Surgical residents then work for 5 more years working 100+ hours a week.