At her blog, Science Professor contemplates how researchers react to the unsavory actions of other scientists. Specifically, when drafting a manuscript, she wonders whether "citing a creep somehow condones [that person's] creep-ish behavior." Science Professor says that even if a disgraced researcher's science has not been affected by his or her perceived ethical lapse, it could affect "how you feel about the research, but also how others perceive the work," based solely on the cited author's association to some misgiving.
Science Professor asks "are there ways in which you are influenced in your research decisions — major or minor — by your feelings about someone's reprehensible behavior outside of the research sphere?"
In the comments, Kea says that, professionally speaking, it's best to "just cite creeps and get on with it." HFM, however, says the situation can be much more nuanced. "If there's a marginal citation, sure, might as well give it to the non-creep. But if key background came from the creep, even if they had only one good idea in their life and spent the rest of their time drop-kicking kittens, then you're stuck." HFM adds that the situation becomes especially sticky when collaborators are involved. "Not just because I'd have to work with this person, but because I'd be helping them."
DrDoyenne says that when it comes to citing another's work, "even [if] I despised someone for personal reasons, I would probably grit my teeth and make the decision based on professional merit."