There is a simple reason for this: White people older than 25 try to have respect for other people in general. That is the way we were raised. I can’t speak for other races, but I know that white kids under 25 are worried about image. Being considerate of others is not one of them. It is a shame that thinking of other people gets made fun of. As for the actual trotting, people who don’t want to ‘run’ most likely ‘trot’ in an effort to speed up their travel time.