A good way to get over one' s fear of an activity one finds terrifying is to do it repeatedly. For instance, over half of people who have parachuted only once report being extremely frightened by the experience, while less than 1 percent of those who have parachuted ten times or more report being frightened by it.
The reasoning in the argument is most vulnerable to criticism on the grounds that the argument neglects to consider those people who have parachuted more than once but fewer than ten times.