People decide to donate their body for plastination after death for very diverse reasons:
My body is too valuable to be burned or buried in the ground. This instruction is my own free will.
It is nice to know that my body will still serve a good purpose after my death. I would like to thank the people who make this possible.
The body is only the shell that makes up a person. After death, it is important to live on in the memory of the bereaved. In my opinion, we do not need a grave, a tombstone or a place where we mourn or remember for this.
I myself am a recipient of an organ donation (kidney) and with the donation of my body want to be useful for science and teaching.