I never said the procedure should be forced on everyone. It should be assumed as the default decision. Those who choose not to donate organs - for whatever reason - could carry a card, wear a piece of jewelry, or some other means of identifying that they don't want their organs disturbed.
You talk about having control over your body and your organs, but I think the very definition of death is losing that control. When you die, your body is not your own anymore. It becomes trash for the rest of humanity, a mere thing to be disposed of in very specific (and expensive) fashion.
If you're indigent (meaning that you have no money, insurance, or relatives willing to pay for the disposal of your corpse) then I'd say it's pretty got-dang selfish to expect the public to dispose of you respectfully without offering squat in return.
I'm all in favor of people having absolute power over their own bodies, but only while they're alive. When you're dead, your body is no more precious or sacred than a picked vegetable - less so, in my opinion, since a decaying human is much more bio-hazardous (and funky) than its weight in rotting turnips.