A death wish and low self esteem?
Seriously, I think being a medicine chief is one of the worst jobs ever. You have the responsibilities of a junior attending, an asst PD, a punching bag (for everyone in the hospital who has a beef w/ the IM program/residents) and a grief/trauma counselor all wrapped up in a tidy $50K/yr package.
If you're looking for a gig that will give you a better shot at an academic general IM job, do a Gen Med Fellowship. Same money, half the responsibility.
Don't get me wrong, I'm glad there are people who want to be Chief Residents (in the same way I'm glad there are people who want to be Pediatricians, OBs and surgeons of all stripes) but I'm even more glad that it's not me.