Why is benefit-cost analysis so abhorrent?

Psychologist Bruce Hood interviewed by REASON:

REASON: One example that you give in the book is the case of a child who needs medical attention that will cost $1 million, which the hospital will have to cover. You describe this phenomenon where most people not only have the instant intuition that the child should be saved no matter what, but they are actually disgusted by anyone who tries to do a cost-benefit analysis on the question, even if that person comes to the "right" conclusion in the end.

HOOD: It was Philip Tetlock, who is an economic psychologist, who first pointed that out. The fact that you might deliberate over it, the fact that you might even have to apply some kind of cost benefit analysis is in itself abhorrent. Because it's a violation of what should be an instantaneous assumption, something that the group should automatically feel. Leon Kass called that the gut reaction, the politics of decision making, that you should just feel the answer to be correct. These are all driven by intuitions. The moral disgust that we feel is again something that you shouldn't have to think about. But that's really quite arbitrary, because in many ways—I think the hospital administrator example is perfect for that—in terms of what's best for the group, it's clear that these are tough decisions. In fact, it's clearly a decision that people do agonize about. But if you put them into the open domain they'd be very reluctant to say that or to admit that publicly. But that's in fact exactly what does have to go when you're in a position to hold the purse strings.