I hate when this gets brought up, because it inherently implies that we can't improve them. Everyone talks about increases in handoffs causing increases in medical errors. I think handoffs have a long way to go, and we need to better utilize technology to help in this (ie make better EMRs).
The overworked doctor is just as bad IMO. I've been there on solo 28 hour calls going on my 11th admission. In the morning I'm next to useless and my handoff to that team was less than stellar.
I've heard a few other similar stories from him as well. Doctors have immense political power; if hospitals are grinding them to dust, it's because doctors as a group are letting them (the good old 'seniors don't care that juniors are getting crushed' problem). From my own limited experience working with them as a neuro tech, doctors will close ranks quickly against outside forces, but plenty will sell each other out within the profession. For every haggard ED doctor, there's a specialist somewhere making cushy deals with the administration.
Now, that doesn't seem to justify the fact that long hour shifts are placed so close together. It seems like you could give doctors a longer break in between shifts than they have. Residents have the worst of it. The attending actually do get a fair amount of time on/off. Residents already work a lot less than they did 50 years ago, some think that their training should be extended to cover the loss of density.