When I first began formally training people, there was this trainer I worked with who was about the biggest douchebag I've ever seen. He was annoying, moody, rolled up the sleeves of his shirt (revealing nothing, by the way) and in all honesty, a real asshole to people. You never wished any real harm on him, but you wouldn't be sending him flowers if a car rolled over his foot, breaking every bone.
Well this guy, who we will call Troy (we will do so because it's his real name) used to tell everyone how great this exercise was for the lats and used some scientific mumbo-jumbo to explain to his clients, most of who were trophy wives that could care less. Amusing for the first couple of hours of the day, it was (to speak Yoda speak). For the rest of my year long stay...that is why firearms should be illegal.
So everytime you want to do this exercise, remember Troy and his annoying ways.
