In todays world it is all about "Am I Going To Get Paid." They do not take chickens for payment anymore.
I doubt many doctors are in it for the money, sure if you work really really hard you can get to a point where the money is worth it, but for most doctors the work you put in, the amount of your life you give up is far beyond the pay out compared to what a person as smart as them could be getting in another field. I think that at least originally most doctors either felt passionate about the science of medicine, or about helping others, even if it has become mundane for them over the years, so deep down, even if they dont feel the passion anymore, they should still feel a desire to help, and this is evident with most doctors i have met, they dont have the passion anymore, but they still care on some level, they put in a tiny bit more effort and help out in ways they not really HAVE to to get paid.<br />
I suppose it's like any profession where you are paid to care, you will always wonder how much of their motivation is money and how much is the want to help, but i think in most cases, "caring" professions would drive someone insane if they didnt care beyond looking for a paycheck.
Its mandatory for new doctors to do a 3 year contract in rural towns here. They don't get paid near as much as they would in a city. If you have medicare then seeing a Doctor is free. Thereabouts.