Three illustrations of why scientists need to know history:
 Biologists often appeal to founders in the field such as Darwin or Haeckel, either as a point of contrast or as intellectual ancestor - but are their depictions accurate?
 Scientists need to know the nature of the scientific practice, e.g., the refutations of well accepted theories, the failures, the dead ends.
 Terms like "fitness" may be loaded with historical baggage that scientists are not aware of, but which affects their reception.--Roberta Millstein. [Numbers added to facilitate discussion.--ES]
The image(s) of science that philosophers of (the) science(s) describe and promote often has an afterlife in (the) science(s).
Ever since Kuhn projected his experiences within and about physics onto a persuasive and widely discussed image of science, philosophers of science and the scientists that embrace Kuhn and his image [see here], have thought that progressive science requires certain features (paradigmatic consensus, mythic history, puzzle-solving, etc.)* In the exchange over her post, Millstein offered three reasons for thinking that praticing scientists need to know an accurate history. Let's grant a critic that  is not very persuasive. For those kind of appeals are primarily rhetorical techniques; there is a sense in which the truth does not matter in such appeals. Let's grant a critic that  can be achieved without knowledge of history (which now is conceived as a repository of error). So,  is not intrinsic to scientific practice, but it does not mean that history does not have this useful, therapeutic role.