I think there's probably a more fundamental difference between scientists/researchers and doctors. If a researcher discovered a drug that was able to cure, for example, small cell lung cancer, how exactly would he have the skill to take a history, do an examination, examine radiographs, and then administer the drug to relevant patients? Doctors "save lives" by applying research already done, but that doesn't mean they play a smaller role than the people who originally discovered a drug that they're giving. Two parts of the same puzzle... wholesale and resale, so to speak.