The change would take from prison staff an important tool for keeping prisoners in line. It's like imposing a tougher sentence on the prison guards. DOC may be correct that physical contact is a privilege, not a right. But no one suggests that the privilege has been widely abused. What the current policy has done, instead, is make the interim between the crime and imposition of death more bearable for prisoners' spouses and children.
Society has good reason to penalize killers.