Just to play devil's advocate (and to ask convenience questions which I'm sure there are answers to):
- what if your liver goes to someone who's abused their body over someone who hasn't?
- what if your organ goes to someone you don't approve of, e.g. a mastermind criminal
- what if you are prolonging someone who's just not fit for life and is costing more money in the long run?
None of these arguments are very compelling, really.
All manner of people abuse their body. Good people, bad people, average people. People also grow out of bad habits. Addicts turn turn their life around. There is always a chance a person can change even without a massive life changing operation. I have done. And who knows, the gift of a second chance at life might even inspire them to change if they wouldn't have otherwise. But anyway, who doesn't abuse their body a little bit?
And no amount of money is more valuable than a life. That's a no-brainer.