I read a thread similar to the above on r/Canadaleft. In Canada, blood donations are not compensated (beyond cookies and juice), and are collected by a single government agency. Healthcare in Canada is free at the point of service, so people who need blood or plasma get it at no cost.
To me this seems like a good idea, I don't want there to be a price on body products. It seems bad to be that blood, or kidneys, or any human organ could be sold or bought.
On the other hand, isn't giving blood or plasma a form of labor? Should a system rely on charity to function?
Plasma is bought/sold in the United States, often sourced from the poor. But organs cannot be bought. In some countries organs can be bought.
Many western countries ( Canada included) buy plasma from the United States, because domestic donation rates are too low. So the high horse isn't even really that high.
Can a smarter leftist provide some insight?
I agree, although I think in a society that guaranteed people's basic needs like food, housing and healthcare, these issues would not be strong enough to lead people to risk their lives, and if the government payed for it, it would lead to increased participation.