It is always to be a centrist. The problem is that there is some moral dubiousness between being a centrist between good and evil, or right and wrong. Germans who avoided killing Jews, but made a point not to get involved with the extremists who tried to overthrow Hitler, were centrists – and are still apologizing for it.
Would you want a doctor who considered an effective treatment and doing nothing, and being a centrist decided on a somewhat effective treatment? Doing a little bit of the right thing is very centrist, and very hypocritical.