I believe that is why it is more of a first come, first served type of system, even tho it means there are many faults with the system as the article points out. If my liver goes to a murderer, I'll still have saved a life. Maybe that murderer will repent. Maybe he/she will sit in jail and with all the free time on their hands, come up with a plan to save the planet, you just never know.
That brings up an interesting point. It is well known that organ recipients pick up traits of the organ donor. For example a sudden interest in sports that the donor had or a taste for a certain food, etc. So what would happen if the heart of the nicest person in the world was transplanted in to a serial killer?