Then, frankly, it's your own fault, the same as people who don't bother writing a will....
But if you don't write a will, then your estate is normally left to your next of kin, or distributed among your children. It isn't given to random strangers. In any case, donating your organs when you die is doing society a service. Why is doing a purely optional service for society suddenly the "default"? It's because the people writing these laws know that if they can pass them quickly and quietly, then millions of people who already drive won't hear about this, and will have no idea that they have to take the initiative to stop their organs from being taken from them upon death. When I was learning to drive, the instructor briefly mentioned that if you wanted to be a donor, you had to go and fill out a form to make it official. That was it for me, and I assume for the millions of people who already have a license. Why would all those people randomly think to themselves, "Hmm, I wonder if they've changed the laws on being a donor. I had better go and check"? This is like fine print on a contract. It's sneaky, and it's dishonest.
...that doesn't change the fact that the dead person is the one who rightfully owns the organs.
The dead have ownership?
Yes, they certainly do.
What is wrong with legalizing the organ market. It's your body, therefore you have the right to do with it what you want. If you want to sell a kidney, you should be able too.
Men can sell their sperm, women can sell their eggs, make a shit load of money off of it too, and doing so ends up genuinely helping people who cannot have children on their own. Why are organs off the table?
Just out of curiosity, have you ever donated sperm? You're paid a very small amount purely as a gratuity, and there are very strict rules governing the process (for example, you can't jerk off for a few days prior to your donation). You can't make a "shitload" of money doing it. As for organs, well, I thought this would be kind of obvious, but if organs can be sold, then people will start carving up others to steal organs to sell.