China's human rights are not the same as Canada's. When you kill somebody and take their right to life away, you basically forfeit your rights. It's like this in other parts of the world too... not just China.
What would you have prisoners do? Go to jail and become a better criminal or go to jail and work and better the country? How many criminals actually come out rehabilitated? Very few, otherwise we wouldn't have sex offender registries to track people when they come out. Why track them? Their rehabilitated! Right?
If you or your family needed an organ transplant... you wouldn't be complaining. Seeing as how North Americans are getting so obese nowadays, you should be thanking China for the heart donors.