How would you feel if someone kidnapped your child or wife and after slaughter sold their organs piece by piece for profit and you never find a trace of the corpse of your beloved one?
Also many times the black market dealers to overcome the morale objections of the patient present to him a fake story like "Samuel" and sell to him the organs of a killed innocent victim instead.
If all of us become organ donors and no patient agrees to buy one, the black market will disappear and the timeframe for a transplantation would be very good.
EDIT: Also i don't want to strengthen the accusation that the bitcoin is a means to support illegal activities.
I wouldn't like it very much at all....don't think anyone in their right mind would.
A world full of consenting organ donors is an ideal we can work towards, unfortunately I don't see it happening anytime soon.