Just to remind you: the great Civil Rights era cases were all plants, and care was taken by the organizers to find a presentable defendant with a clean record. Lady Chatterley was a plant, too.
I think people are more disgusted by how self serving the "plant" is. Rosa Parks sat in the front of the bus to support a movement. Ahmed Mohammed brought a dismantled clock in a suitcase to school to further the political ends of his father's career.