As for the motivations of researchers:

If any student comes to me and says he wants to be useful to mankind and go into research to alleviate human suffering, I advise him to go into charity instead. Research wants real egotists who seek their own pleasure and satisfaction, but find it in solving the puzzles of nature.

--Albert Szent-Györgyi

My [indefensible] impression is that altruistic culture is a strong part of the reason why the quality of biomedical researchers is so poor, and cancer research funding is so often near-fraudulent.