This is wrong on so many counts, but I’ll stick to just three quick replies.
First, as speech and debate professor Dr. Marc Newman points out, every speech textbook on the planet acknowledges the importance of visual aids in speeches where words alone are not adequate to describe something (“The Great Abortion Debate,” p.78).
Second, formal academic debates are not forensic competitions (tournaments with multiple teams) where random topics are assigned mere moments before the event. Rather, academic debates allow each speaker weeks to research his position and present the best case possible, using whatever evidence is relevant in the Socratic quest for truth.
Third, even in court cases, graphic images are admitted as evidence, despite the emotional impact on the jury. Associated Press reports that jurors in the trial of Andrea Yates, the mother who drowned her five young children in a bathtub, will view numerous pictures of the crime scene. One of the photos shows 7-year-old Noah Yates floating face down in the bathtub with his arms outstretched, submerged beneath the water. Others detail bruising on the children and how the bodies of Noah's four younger siblings — John, 5; Paul, 3; Luke, 2; and Mary, 6 months — were laid out on a bed in the back bedroom. State District Judge Belinda Hill said the photos' relevance outweighed any prejudice they might cause the jury (“Judge Allowing Yates Jurors to See Crime Scene Photos,” (AP) February 20, 2002).
To cite another example, gruesome photographs depicting the bloody attack by two frenzied dogs took center stage in the trial of a San Francisco couple accused of letting the animals maul a neighbor to death. Prosecutors displayed images of Whipple's fatal injuries—the back of her neck bloodied and punctured by the dog's teeth, her buttocks and breasts also punctured, her face covered in blood. Prosecutors successfully argued that although the images were disturbing, jurors would not understand the nature of the crime without them (“California Jurors See Dog Attack Victim Photos” (AP), February 20, 2002).
Gregg Cunningham puts it well. “If something is so horrifying we can’t stand to look at it, perhaps we shouldn’t be tolerating it.”