What I've heard is that residency spots are restricted in number by Medicare (who pays hospitals that train residents) under heavy lobbying by the AMA. The rumor is that this is done to artificially restrict the number of MDs in the country thereby raising everyone's salary.
Don't personally know if this is true, but if it is it's shameful, especially given the "physician shortage" crisis. Or maybe crisis should be in quotes.
> What's keeping us from creating more physicians to meet the (obvious) demand?
It takes a lot of money, resources, and existing doctors' time to train a new doctor. One thing that's likely to help a bit is the move to nurse practitioners and physician assistants for much of primary care.
If we had more doctors, it seems that it would also cost less to train more doctors (assuming that more doctors made the average doctor's time less costly). An unfortunate feedback loop there.
Why the hell should you need to pull 24-28 hour shifts?