While I agree that science shouldn't try to give us declarations about what is and isn't moral, I disagree that researchers are necessarily unqualified to advoc

While I agree that science shouldn't try to give us declarations about what is and isn't moral, I disagree that researchers are necessarily unqualified to advocate with respect to their fields. You seem to have jumped to the conclusion that researchers are emotionally attached to their field in a way that prevents them from being objective. I don't see why this should be the case. If anything, competent researchers need to be able to be objective about their research. If a person can't be objective about dolphins, not only should that person not be in a discussion about whether dolphins are people, that person should not be doing research on dolphins. But the input from objective, rational experts, including dolphin researchers, is certainly valuable in a discussion on whether dolphins are people -- as is input from philosophers, animal psychology researchers, and potentially legal scholars. Similarly, I would have a hard time accepting a claim that doctors shouldn't be in a discussion on right-to-die legislation because they must be too emotionally attached to their patients, or that civil rights activists and scholars shouldn't be part of discussions surrounding rights of US held detainees at Guantanamo/Bagram/etc because surely those activists are too emotionally attached to an outcome to be rational.