Why Do People Oppose Organ Markets?

It seems that Bryan thinks most opposition to markets in organs is a function of either ignorance of the likely consequences or perverse and exotic moral premises. This makes me wonder if he has ever debated this issue with anyone? Lots of people understand the economics well enough but continue to believe that markets in organs ought to be illegal.

I have debated the legalization of organ selling with quite a few people over the years. In my experience, 100% of people who can correctly explain economists' standard case for legalization favor legalization, and 100% of people who can't correctly explain the case oppose legalization.

I'll grant that my sample is a little unrepresentative. I suspect that with a little legwork, Will could find a hundred Leon Kass-types who understand the economics of organ selling but still oppose legalization. But I still think that at least 90% of people who can correctly explain economists' case are on board. Am I wrong?